Hearing Loss and Aging


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Hearing Loss and Aging

  1. 1. Hearing Impairment and Elderly PeopleMay 1986NTIS order #PB86-218559
  2. 2. Recommended Citation:U.S. Congress, Office of Technology Assessment, Hearing Impairment and Elderly People–ABackground Paper, OTA-BP-BA-30 (Washington, DC: U.S. Government Printing Office, May1986).Library of Congress Catalog Card Number 86-600511For sale by the Superintendent of DocumentsUS. Government Printing Office, Washington, DC 20402
  3. 3. PrefaceHearing impairment is very common among elderly people and can seriously affecttheir quality of life, personal safety, and ability to function independently. This OTAbackground paper discusses the prevalence of hearing impairment and its impact onelderly people; hearing devices and services that may benefit them; and problems inthe service delivery system that limit access to these devices and services.This background paper is part of the OTA assessment of Technology and Agingin America that was requested by the Senate Special Committee on Aging and the HouseSelect Committee on Aging, and endorsed by the House Committee on Education andLabor. For that assessment OTA selected five chronic conditions for in-depth analysisbecause of their prevalence and severe impact on elderly people and because of thepotential role of technology in their treatment. Hearing impairment is one of these con-ditions; the others are dementia, urinary incontinence, osteoarthritis, and osteoporosis.Many of the chronic conditions that affect elderly people, including the types ofhearing impairment that are most common, cannot be cured with available medicaland surgical treatments, As a result, some elderly people, their families, and othersassume that these conditions are not treatable. Yet assistive technologies can often helpto maintain functioning even when the underlying disease or condition cannot be cured.In the case of hearing impairment, these technologies include hearing aids, infraredand FM assistive listening devices, telephone amplification devices and other telecom-munication systems, signaling and alarm devices, and environmental design and auralrehabilitation techniques. Used singly or in combination, these technologies can facili-tate communication and help to maintain an independent lifestyle for many hearingimpaired people.As more and more Americans live to older ages, the prevalence of chronic condi-tions that cause functional impairment is expected to increase. Along with biomedicalresearch on the causes and possible cures for these conditions, the development andincreased use of technologies that compensate for functional impairment are amongthe most hopeful approaches to improving the quality of life of elderly people.OTA was assisted in the preparation of this background paper by many outsideadvisors and reviewers, including biomedical and social science researchers, physicians,audiologists, and representatives of the hearing aid dealers and hearing aid manufac-turers associations. We express sincere appreciation to each of these individuals andorganizations. As with all OTA reports, the content of this background paper is theresponsibility of the Office and does not necessarily represent the views of outside advi-sors or reviewers.
  4. 4. Technology and Aging in America Advisory Panel*Robert Binstock, Panel ChairDirector, Policy Center for Aging, Brandeis UniversityRaymond BartusGroup Leader of GeriatricsMedical Research DivisionLederle LaboratoriesRobert BerlinerDeanSchool of MedicineYale UniversityRobert N. ButlerChairmanDepartment of Geriatrics and Adult EducationMt. Sinai Medical CenterRobert ClarkAssociate ProfessorDepartment of Economics and BusinessNorth Carolina State UniversityLee L. DavenportSenior Vice President—Chief Scientist,emeritusGTE Corp.Ken DychtwaldpresidentDychtwald & AssociatesCaleb FinchProfessor of Biological Sciences andGerontologyUniversity of Southern CaliforniaVelma Murphy HillDirectorCivil and Human Rights DivisionService Employees International UnionRobert L. KaneSenior ResearcherThe Rand Corp.Paul A. KerschnerAssociate Director for Programs,Legislation and DevelopmentAmerican Association of Retired PersonsMaggie KuhnFounder and National ConvenerThe Gray PanthersMatt LindVice PresidentCorporate Planning and ResearchThe Travelers Insurance Co.Robert G. LynchVice PresidentMarketing PlanningGTE Corp.Mathy D. MezeyDirectorTeaching Nursing Home ProgramUniversity of PennsylvaniaHamish MunroProfessor of Medicine and NutritionTufts UniversityBernice NeugartenProfessor of Education and SociologyNorthwestern UniversitySara RixDirector of ResearchThe Women’s Research and EducationInstitutePauline RobinsonResearch Professor of GerontologyUniversity of Southern CaliforniaJohn W. RoweChief of GeriatricsBeth Israel HospitalBert SeidmanDirectorDepartment of Occupational Safety, Healthand Social SecurityAFL-CIOJacob SiegelSenior ResearcherCenter for Population ResearchGeorgetown Universityq Panel members’ affiliations are listed at the time the assessment began.NoTE: OTA appreciates and is grateful for the valuable assistance and thoughtful critiques provided by the advisory panel members Theviews expressed in this OTA report, however, are the sole responsibility of the Office of “technology Assessment.iv
  5. 5. OTA Project Staff—Hearing Impairment and Elderly PeopleRoger C. Herdman, Assistant Director, OTAHealth and Life Sciences DivisionGretchen S. Kolsrud, Biological Applications Program ManagerRobert A Harootyan, Project DirectorDavid McCallum, * Project DirectorClaire W. Maklan, AnalystKatie Maslow, AnalystChris Elfring, EditorSupport StaffSharon Smith, Administrative AssistantLinda Ray ford, Secretary, Word Processing SpecialistBarbara Ketchum, Clerical AssistantRelated ProductsTechnology and Aging in America, OTA AssessmentImpacts of Neuroscience, OTA Background PaperTechnologies for Managing Urinary Incontinence, OTA Case StudyPrqf>rt Director until September 1983v
  6. 6. AcknowledgmentsThis project has benefited from the advice of many experts in the field of hearing impairmentand hearing services. OTA especially would like to thank the following advisors, reviewers, and con-tractors for their assistance and support.Gay BeckerAging Health Policy CenterUniversity of CaliforniaSan Francisco, CADerald BrackmannOtologic Medical GroupLos Angeles, CAScott C. BrownGallaudet Research InstituteWashington, DCAnthony DiRoccoNational Hearing Aid SocietyLivonia, MIDennis DreschlerWayne State UniversityDetroit, MIGeorge W. FellendorfFellendorf AssociatesWashington, DCRaymond M. FleetwoodHarry Diamond LaboratoryAdelphi, MDRichard M. FlowerDepartment of OtolaryngologyDivision of Audiology and SpeechUniversity of CaliforniaSan Francisco, CALaurel E. GlassCenter of Deafness: Research, Training, andMental Health ServicesUniversity of CaliforniaSan Francisco, CAJerome C. GoldsteinAmerican Academy of Otolaryngology-Headand Neck SurgeryWashington, DCSandra Gordon-SalantHearing and Speech Sciences DepartmentUniversity of MarylandCollege Park, MDElise HallMontgomery County Department of Housingand Community DevelopmentRockville, MDAnnette G. van HilstMontgomery County Department of Housingand Community DevelopmentRockville, MDLeonard JakubczakNational Institute on AgingBethesda, MDSam KinneyThe Cleveland ClinicCleveland, OHBarry LeshowitzDepartment of PsychologyArizona State UniversityTempe, AZThomas J. MaronickFederal Trade CommissionWashington, DCRalph F. NauntonCommunicative Disorders ProgramNational Institute of Neurological andCommunicative Disorders and StrokeBethesda, MDRobert J. NewcomerAging Health Policy CenterUniversity of CaliforniaSan Francisco, CASuzanne M. PathyThe Suzanne Pathy Speak-Up InstituteNew York, NYCarol M. RodinHearing Industries AssociationWashington, DCDavid SaksOrganization for the Use of the TelephoneOwings Mills, MDvi
  7. 7. Virginia W. SternProject on the Handicapped in ScienceAmerican Association for the Advancement ofScienceWashington, DCRocky StoneSelf Help for Hard of Hearing PeopleBethesda, MDJerry TobiasAuditory DepartmentNaval Submarine Medical Research LaboratoryGroton, CTGwenyth R. VaughnAudiology-Speech Pathology ServiceBirmingham Veterans Administration MedicalCenterBirmingham, ALTimothy J. WatersMcDermott, Will, and EmeryWashington, DCBarbara WilliamsOffice of Cued Speech ProgramsGallaudet CollegeWashington, DCPeggy WilliamsAmerican Speech-Language-Hearing Assoc.Rockville, MDHoward ZubickBrigham and Womens HospitalBoston, MAvii
  8. 8. ContentsPageCHAPTER 1: Overview . . . . . . . . . . . . . . . . . . . . . 3The Scope and Impacts of HearingImpairment in Elderly People . . . . . . . . . . 3Summary of Major Findings and Issues. . . . . . 4CHAPTER 2: The Epidemiology of HearingImpairment in Elderly People . . . . . . . . . . 11Types and Causes of Hearing Loss AmongElderly People . . . . . . . . . . . . . . . . . . . . .Measuring Hearing Impairment . . . . . . . .Prevalence . . . . . . . . . . . . . . . . . . . . . . . . . .Age , . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Gender . . . . . . . . . . . . . . . . . . . . ... , . . .Race . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Income . . . . . . . . . . . . . . . . . . . . . . . . . . .Institutionalization . . . . . . . . . . . . . . . . . .Prevalence of Tinnitus . . . . . . . . . . . . . .The Impact of Hearing Impairment , . . . .Clinical Impact . . . . . . . . . . . . . . . . . . . . .Psychosocial Impact . . . . . . . . . . . . . . . .Denial of Hearing Impairment. . . . . . . .Deafness . . . . . . . . . . . . . . . . . . . . . . . . . . .CHAPTER 3: Treatment of HearingImpairment. . . . . . . . . . . . . . . . . . . . . . .Prevention . . . . . . . . . . . . . . . . . . . . . . . . . .Medical and Surgical Treatment. . . . . . . .Treatment of Conductive HearingImpairments . . . . . . . . . . . . . . . . . . . .Treatment of Sensorineural HearingImpairments . . . . . . . . . . . . . . . . . . . .Hearing Aids . . . . . . . . . . . . . . . . . . . . . . . .Problems in Hearing Aid Design andPerformance . . . ..., , , ..., ., , , ., ,Problems in Selecting the AppropriateHearing Aid.. . . . . . . . . . . . . . . . . . . .Problems in Adjusting to a Hearing AidAssistive Listening Devices . . . . . . . . . . . .Telecommunication Devices . . . . . . . . . . .Signaling and Alarm Devices. . . . . . . . . . .Assistive Device Development. . . . . . . . . .Environmental Design ., . . . . . . . . . . . . . .Aural Rehabilitation . . . . . . . . . . . . . . . . . .Hearing Aid Orientation . . . . . . . . . . . . .Auditory Training . . . . . . . . . . . . . . . . . .Speechreading . . . . . . . . . . . . . . . . . . . . .Counseling . . . . . . . . . . . . . . . . . . . . . . . .CHAPTER 4: The Service Delivery System .Service Providers and Referral Patterns .Physicians. . . . . . . . . . . . . . . . . . . . . . . . .Audiologists . . . . . . . . . . . . . . . . . . . . . . .Hearing Aid Dealers . . . . . . . . . . . . . . . .. . . . 11. . . . 13. . . . 14. . . . 14. . . . 15. . . . 15. . . . 16. . . . 16. . . . 16. . . . 17. . . . 17. . . . 18. . . . 19. . . . 20. . . . 25. . . . 25. . . . 27. . . . 27. . . . 27. . . . 2831. . . . 32. . . . 32. . . . 33. . . . 36. . . . 39. . . . 40. . . . 41. . . . 41. . . . 41. . . . 42. . . . 42. . . . 43. . . . 47. . . . 48. . . . 48. . . . 49. . . . 50PageReferral Patterns , . . . . . . . . . . . . . . . . . . . . . . 51The Role of Other Health Care and SocialService Providers . . . . . . . . . . . . . . . . . . . . 52Settings for Service Delivery. . . . . . . . . . . . . . . 54Health Care Settings . . . . . . . . . . . . . . . . . . . . 54Educational Settings . . . . . . . . . . . . . . . . . . . . 54Community Agencies . . . . . . . . . . . . . . . . . . . 55Alternate Approaches to Service Delivery. . . . 55Veterans Administration Hearing Services. . 55Elderhostel Program for the HearingImpaired . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Assistive Device Centers. . . . . . . . . . . . . . . . . 56Self-Help Groups for Hearing ImpairedPeople , . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57Nursing Home Initiatives . . . . . . . . . . . . . . . . 57Screening Programs . . . . . . . . . . . . . . . . . . . . . . 58Regulation of the Delivery System . . . . . . . . . . 58CHAPTER 5: Funding for Treatment ofHearing Impairments . . . . . . . . . . . . . . . . . 63Medicare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Medicaid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Other Government Funding Programs. . . . . . . 65Private Insurance . . . . . . . . . . . . . . .Where Services Are Provided andBy Whom. . . . . . . . . . . . . . . . . . .Type and Purpose of Services . . . .Role of the Physician . . . . . . . . . . .CHAPTER 6: Conclusion . . . . . . . . . . . .APPENDIX A:APPENDIX B:REFERENCESTablesTable No. Sources . . .Assistive Device Centers. . . . . . . . . . . . . . . . . . . . .. . . . . . . . 66. . . . . . . . 66. . . . . . . . 67. . . . . . . . 67. . . . . . . . 71. . . . . . . . 75. . . . . . . . 77. . . . . . . . 83PageCauses of Conductive and SensorineuralHearing Impairments. . . . . . . . . . . . . . . . . . . . . 11Hearing Loss in Decibels Related toApproximate Degree of Impairment . . . . . . . . 13Prevalence of Hearing Impairment, IncludingTinnitus, in the Civilian, NoninstitutionalizedPopulation, by Race and Selected AgeGroups, United States, 1977 . . . . . . . . . . . . . . . 16Types of Hearing Aids Sold in the UnitedStates, 1984 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Proportion of Hearing Aid purchasersby Age, 1983-85 . . . . . . . . . . . . . . . . . . . . . . . . . 30Persons Age 65 and Over Who Use aHearing Aid, United States, 1977. . . . . . . . . . . 31...Vlll
  9. 9. Table No.7. Satisfaction With Hearing Ability Using aHearing Aid . . . . . . . . . . . . . . . . . . . . . . . . . .FiguresFigure No.1. Structure of the Ear . . . . . . . . . . . . . . . . . .2. Prevalence of Hearing Impairment,Including Tinnitus, in the Civilian,Noninstitutionalized Population,United States, 1977 . . . . . . . . . . . . . . . . . . .3. Prevalence of Hearing Impairment AmongAdults by Frequency of Tone, UnitedPage Figure No. Page5. Cochlear Implant in Place. . . . . . . . . . . . . . . . 2831 6. Hearing Aid Types . . . . . . . . . . . . . . . . . . . . . . 297. Hardwire Device forOne-to-One Consultation . . . . . . . . . . . . . . . . . 34Page 8. Audio Loop Wand Receiver . . . . . . . . . . . . . 3411 9. FM Persona] Amplification Device:10.14 11.12.States, 1971-75 . . . . . . . . . . . . . . . . . . . . . . . . . 154. Prevalence of Tinnitus, by Severity and 13.Selected Age Groups, United States, 14.1960-62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Transmitter and Receiver . . . . . . . . . . . . . . . . 34Infrared Amplification Device:Transmitter and Receiver . . . . . . . . . . . . . . . . 35Three Types of Telephone AmplificationDevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Sonic Alert Signaling System, Including aPaging Device and Door Bell Signaler . . . . . . 39Lip Reading Glasses . . . . . . . . . . . . . . . . . . . . . 43Materials Supplied to Participating Hospitalsby the Suzanne Pathy Speak-Up Institute. . . 53ix
  10. 10. Chapter 1Overview
  11. 11. Chapter 1OverviewTHE SCOPE AND IMPACTS OF HEARING IMPAIRMENTIN ELDERLY PEOPLEHearing impairment is a serious problem amongelderly people in the United States. It is the thirdmost prevalent chronic condition among the non-institutionalized elderly population, exceeded onlyby arthritis and hypertensive disease (118, 120,122).Elderly people are much more likely to have ahearing impairment than younger people. Slightlymore than 1 percent of all people under 17 yearsof age suffer some hearing impairment. But prev-alence rises to about 12 percent of all people be-tween 45 and 64, about 24 percent of those 65 to74, and about 39 percent of those 75 and over(121).1The prevalence of hearing impairmentamong elderly people in nursing homes is evengreater (98).While only 11 percent of the Nation’s popula-tion is over 65, about half of all hearing impairedpeople are over 65 (41). As this older segment ofthe population grows, the number of hearing im-paired individuals will rise dramatically. The over-75 population, which has the highest prevalenceof hearing impairment, is growing at a faster ratethan the elderly population as a whole, thus in-creasing the number and proportion of hearingimpaired people in the population. At present,about 7 million elderly persons have significanthearing loss. If current rates persist, by the year2000 more than 11 million elderly persons will besignificantly affected.Hearingimpaired individuals include those whoare deaf_ and those who are hard-of-hearing. Hard-of-hearing refers to a partial hearing loss that re-sults in difficulty with speech comprehension, al-though some auditory function remains. Deafrefers to a degree of impairment that renders hear-1’1 hese figures are hased on the results of interfiew sur~qvs. Fkti -matw of prekalenc(’ basfxi on audiometric testing art’ ronsiderahl)higher. (;h. 2 disrusses the differences hett$reen thr prclakmrc esti-m a t e s deternlined I)j these tt~o mf~thrds ot’ m e a s u r i n g h e a r i n gat)ilitting nonfunctional for ordinary purposes of life(117). Most people with hearing impairments arenot deaf, but even the partial hearing loss that iscommon among elderly people can limit their in-dependence and reduce the quality of their lives,Although hearing impairment is not life-threat-ening and does not directly restrict physical activ -ity, it can cause severe disability. Hearing loss limitsa person’s ability to interact socially with familyand friends and to receive and interpret informa-tion (10). Many warning devices such as fire alarmsrely on sound signals. Furthermore, hearing is animportant method of identifying dangers in theenvironment, such as approaching vehicles. Thus,hearing impairment can affect personal safety. Itcan also interfere with important activities of dailyliving, including shopping; using public transpor-tation; and communicating with health care pro-fessionals, tradespeople, and community serviceproviders. When hearing impairment limits a per-son’s ability to function independently, it can re-sult in a need for formal and informal long-termcare services.The importance of hearing and the problemsposed by hearing loss in elderly people have longbeen recognized. In 1968, the Senate Special Com-mittee on Aging noted the high prevalence of hear-ing loss among elderly people and directed its at-tention to three problem areas: 1) delivery ofservices to older people with hearing loss; 2) hear-ing aid sales; and 3) the effects of increasing noiseon future generations of Americans (127). Duringthe past 18 years we have made some progresscombatting these problems, but much remains tobe done.This background paper examines the kinds ofhearing impairments that are most common amongelderly people and the technologies that are avail -able to compensate for them. Chapter 2 reviewsthe types, causes, and prevalence of hearing im-pairment and its impact on elderly people. Chap-3
  12. 12. 4ter 3 discusses treatment methods, including pre-vention, medical and surgical treatments, anddevices and procedures to compensate for hear-ing loss. These include hearing aids, assistive listen-ing devices,2telecommunication devices, and auralrehabilitation techniques. The chapter also dis -2Assistiw listening devices are devices that transmit amplifiedsound more directly from its source to the listener; examples areaudio loops, infrared, and radio frequencj’ (Ahl and F%f) devices (74).SUMMARY OF MAJORThe Federal Government is concerned abouthearing impairment among elderly people becauseof its impact on their safety, quality of life, andability to live independently. Federal initiatives thathave addressed the problems of hearing impair-ment include funding for research, legislation toguarantee access to public facilities for hearingimpaired people, and regulation of hearing aidsales. These efforts have benefited hearing im-paired individuals of all ages. In addition, somefunding is available to treat hearing disordersthrough Medicare, Medicaid, the Veterans Admin-istration (VA), and other Federal programs.Despite these Federal programs, many elderlypeople with hearing impairments are not receiv-ing appropriate treatment or using potentially ben-eficial devices. Some do not seek treatment becausethey are not aware of their hearing loss or becausethey believe that nothing can be done to treat orcompensate for it. Negative social attitudes aboutgrowing old and becoming hard-of-hearing causesome elderly people to deny their hearing impair-ments. Others are aware of their hearing loss butavoid the use of hearing aids and assistive listen-ing devices because they do not want to call atten-tion to their loss.Public education is needed to increase aware-ness about the extent and types of hearing im-pairment among the elderly. Elderly people, theirfamilies, and health care professionals also needinformation about treatments, devices, and serv-ices that can compensate for hearing impairment.Federal, State, and local governments, private in-dustry, and organizations representing elderly andcusses obstacles to the use of these technologiesand looks briefly at problems of device develop-ment. Chapter 4 describes the existing systems thatprovide treatment for hearing impaired people,including the service providers, settings, and pat -terns of service delivery. The chapter emphasizesthe need for improved delivery systems that areadapted to the needs of elderly people. Chapter5 discusses funding for hearing devices andservices.FINDINGS AND ISSUEShearing impaired people must share responsibil-ity for public education programs that promoteawareness of the problem and encourage the useof appropriate treatments, devices, and services.Self -help groups are an increasingly strong andeffective force in promoting awareness of hear-ing impairment and the needs of hearing impairedpeople. While self-help groups for deaf people haveexisted for some time, groups for people with par-tial hearing loss have developed more recently.Some of these groups are organized on a nationallevel, sometimes with local chapters, while othersfunction only on a local level. One example of anational group is Self Help for Hard of HearingPeople, an organization with more than 15)000members and 170 local chapters and affiliates in41 States.While self-help groups differ in their primaryfocus and mode of operation, they tend to empha-size several important points:qqqthe severe impact of hearing loss on many in-dividuals;the need for hearing impaired individuals toadmit their hearing impairments, to overcomethe sense of shame that many hearing im-paired people feel, and to be more assertiveabout their communication needs; andthe need for families, friends, and others whointeract with hearing impaired people to beaware of and use devices and communicationtechniques that promote effective communi-cation.Self-help groups also stress the heterogeneityof hearing impaired people, both in terms of the
  13. 13. 5oto credit. Pete Souza, The White HousePresident Reagan has acknowledged his hearing loss and is using a small, canal-style hearing aid to compensate forit. By his example, the President has encouraged other hearing impaired people to acknowledge their impairments andconsider the use of a hearing aid or other hearing assistive device for themselves., :t t.,. ~ :I~ tSouza. The White
  14. 14. 6type and severity of each individual’s hearing lossand other physical, emotional, and social charac-teristics of the person and his environment thataffect his communication needs. This hetero-geneity creates a need for a variety of hearing de-vices and services and a process for determiningthe needs of each individual. Self-help groups pointout that the hearing impaired individual is usu-ally the best source of information about his hear-ing loss and that too little attention has been paidto what hearing impaired people, especially thosewith partial hearing loss, say about their needs.In addition to increased awareness of hearingloss in elderly people, there is a need for increasedresearch. Although the prevalence of hearing im-pairment far exceeds most diseases and disabili-ties of later life, the magnitude of this problem hasnot been reflected in the amount of research thathas been conducted on underlying pathologies,prevention, treatment, and rehabilitation. As a re-sult, the state of the art in this field has progressedmore slowly than in many other fields (10).Most hearing research has been focused on verysevere impairments, and particularly the problemsof deaf children. While the results of this researchare sometimes applicable to elderly people, thecharacteristics of hearing impairments that arecommon in elderly people often differ from thoseof severely hearing impaired younger people. Hear-ing impairment in the elderly is often mild or mod-erate, but it is widespread. It is often progressive,with a gradual onset, and may not be recognizedfor some time. In addition, a significant but as yetundefined number of elderly people have decreasedability to tune out background noise and thus havemore difficulty hearing in noisy settings than youn-ger people with comparable hearing ability (31,44). Finally, hearing impairment in elderly peopleoften coexists with other health problems that cancomplicate treatment and limit the effectivenessof hearing devices. Research focused on the mech-anisms of hearing impairment in elderly peopleand appropriate treatment approaches is needed.Few of the hearing impairments common amongelderly people respond to medical or surgical treat-ment. However, a variety of approaches, such asthe use of hearing aids, other assistive listeningdevices, and aural rehabilitation techniques, canbe used to compensate for hearing impairment.These approaches can improve communicationability even when the underlying problem cannotbe cured.Hearing aids are the most widely used devices,but most people with hearing impairments do notuse hearing aids. Estimates from various studiesindicate that between 8 and 25 percent of hearingimpaired people use a hearing aid3(41, 49,94,119),Some of those who do not use hearing aids havebeen told that a hearing aid will not help them;others deny that they need a hearing aid or resistusing a hearing aid for cosmetic reasons. Still othersbuy hearing aids but never learn to use them andeventually stop trying.Hearing aids function well for many elderly peo-ple but do not compensate for hearing loss in othersforqqqqseveral reasons:Some people buy hearing aids that are not wellmatched to their needs. Sometimes this oc-curs because they purchase an aid withouthaving a complete hearing evaluation to iden-tify their specific hearing deficits. Lack ofMedicare reimbursement for a hearing evalu-ation to select a hearing aid exacerbates thisproblem.Even when a person’s specific hearing defi-cits have been identified, lack of informationcomparing different types of hearing aids canmake it difficult to identify the most appro-priate aid.Hearing aids generally amplify all environ-mental sound, including background noise.Although design modifications can improvethe speech-to-noise ratio, some hearing aidusers continue to have problems tuning outbackground noise.Current hearing aid technology does not al-low custom design of a hearing aid in the waythat eyeglasses can be prescribed and groundspecifically for an individual. Within five years,microprocessor technologies may make “pre-scription hearing aids” available.In addition to hearing aids, assistive listening de-vices such as infrared and FM devices can benefitmany hearing impaired people. These devices can3Estimates of the percentage of hearing impaired people who usehearing aids vary depending on the source of the data and the fig-ure that is used for overall prevalence of hearing impairment,
  15. 15. 7be particularly effective for those with mild or mod-erate hearing loss and in situations where back-ground noise is a problem. Some profoundly im-paired persons can also benefit from them. Yetmost elderly individuals do not know about assis-tive listening devices and the existing service de-livery system does not promote their use. Rela-tively few hearing specialists offer a full range ofthe assistive devices. The VA Medical Center inBirmingham, Alabama, has developed a programto distribute these devices, and hearing specialistsat the center receive inquiries about the devicesfrom hearing impaired people all over the coun-try. They refer many people to hearing specialistsin their local areas, but in some areas there areno specialists trained in the use of these devices(129).Medicare, Medicaid, and private insurance donot reimburse for assistive listening devices or forprofessional adivce to determine which devicesare appropriate. (See ch. 5 for a discussion of fund-ing for hearing devices and services. ) Legislationto provide Medicare and Medicaid reimbursementfor these devices was introduced in Congress in1984 and again in 1985. Many observers doubt thatthis legislation will pass because of current budgetlimitations, but supporters argue that reimburse-ment for these devices would encourage their use,thus increasing the independence of hearing im-paired people and ultimately reducing Federalspending for other services.Aural rehabilitation services, including counsel-ing, training in speechreading,4and hearing aidorientation can help hearing impaired elderly peo-ple by reducing anxiety, facilitating better use ofresidual hearing, and achieving more realistic ex-pectations regarding remediation of hearing loss.Yet few hearing impaired elderly people receiveaural rehabilitation services. Public education andeducation of health care and social service pro-viders is needed to encourage the use of these es-sential services.Hearing impaired people who cannot hear overthe telephone face serious problems. They are notable to talk with family and friends, arrange nec-essary services, and obtain assistance in an emer-gency. Some people with mild or moderate hear-ing loss can manage well with a telephone that hasan amplifier in the handset. Others have hearingaids designed with a “telephone switch”5and theycan use compatible telephones. But not all tele-phones are compatible with hearing aids, and mosttelephones do not have amplifiers. In addition,many hearing aids are manufactured without atelephone switch. Some hearing impaired peopleand hearing professionals advocate Federal legis-lation to require that all new telephones be com-patible with hearing aids. Some also advocatestrengthening the Federal and State regulationsthat require telephone companies to make special-ized equipment available to hearing impaired peo-ple for use at home.Adapting public facilities so they are accessibleto the hearing impaired is an area where progresshas been very slow. Section 504 of the Rehabilita-tion Act of 1973 prohibits discrimination againstdisabled individuals by any program or activityreceiving Federal assistance. The law requires thatall facilities receiving any form of Federal supportmust provide access for people with all kinds ofhandicaps, including hearing impairment (80). Sofar, however, efforts have emphasized adaptingfacilities for people with problems in mobility. Thishas occurred even though the costs of installingan audio loop, infrared, or radio frequency (AMor FM) amplification system is usually minimal.compared to the costs of the major architecturalchanges needed to accommodate people with mo-bility impairments. Although it seems incongru-ous, public funding has been available for architec-tural modifications while the cost of amplificationsystems has been paid primarily by the private sec-tor (10).The needs of older people with hearing impair-ments should be considered in any plans to adaptfacilities for the handicapped. In addition, envi-ronmental design technologies to compensate forhearing impairment could be applied in public fa-cilities. These technologies are discussed in chap-ter 3.4S~)t~(!(’hr-(~acii~~g is another term for lipread ing, The term spcerh -read ing emphasizes that the hearing impaired person l~atrhm+ fa -rial, t h ro;it, ;iml hodk nlmrments of the spwiker in [id{] it ion t{) hisIll) n]otfmlf]nts in o;der to undf:rstand m hat he is s~ijing.5A telephone smitrh, nr ‘“ r st~ritrh ,“ is a feature hui]t into sorllphearing aids that allm~s the aid to pick up electronic signals direct 1)from compatihlp t(>lephon(j re(’ei~er-s, t h u s hypssing thf’ h e a r i n g;i id microphone’ and f’lim in:iting unlid nt ml sound.
  16. 16. 8A final concern is the apparentrivalry among the three groups oftension andhearing spe-cialists: physicians who specialize in hearing dis-orders, audiologists, and hearing aid dealers. Phy-sicians who specialize in hearing disorders aremedical doctors with training in diseases of theear. Audiologists are nonmedical hearing special-ists who have a master’s or doctoral degree in au-diology, the science of hearing, Hearing aid dealersare individuals who sell hearing aids who are nei-ther physicians nor audiologists. This report refersto individuals in each of these groups as “hearingspecialists .“ The training and unique skills of eachof these groups are discussed in chapter 4,Each group plays an important role in provid-ing hearing services for elderly people, The con-tinuing rivalry among them interferes with the de-velopment of service delivery systems that makethe full range of devices and services available tohearing impaired elderly people. Any Federal leg-islation or regulations related to hearing servicesshould discourage this rivalry and encourage thedevelopment of coordinated service delivery sys-tems that use the expertise of each type of hear-ing specialist.
  17. 17. Chapter 2The Epidemiology ofHearing Impairment inElderly People
  18. 18. Chapter 2The Epidemiology of HearingImpairment in Elderly PeopleTYPES AND CAUSES OF HEARING LOSS AMONG ELDERLY PEOPLEHearing impairment can be partial or complete.It can be unilateral (one ear) or bilateral (both ears),temporary or permanent, stable or progressive.Types of hearing impairment include conductive,sensorineural, mixed, and central processing dis-orders. These types are based on the site of struc-tural damage or blockage (see figure 1). Conduc-tive hearing impairment involves the outer and/ormiddle ear. Sensorineural impairment involvesdamage to the inner ear, the cochlea, and/or thefibers of the eighth cranial nerve. A mixed hear-ing impairment includes both conductive and sen-sorineural components. Causes of conductive andFigure 1 .—Structure of the EarMalleusItubeMiddle IOuter Ear Ear Inner EarIn the healthy ear, sound waves gathered by the outer ear are trans-mitted through the eardrum and three small bones in the middle ear—the malleus, incus, and stapes—and into the inner ear. There soundis converted from vibrations into electrical impulses by tiny sensoryreceptors, called hair cells, in the cochlea. The electrical impulsespass through the eighth cranial nerve Into the auditory centers of thebrain.SOURCE Vlckl Friedman, Washington University Medical Center at St. Louissensorineural hearing impairment are listed intable 1.A central processing disorder is a hearing im-pairment that influences complex aspects of hear-ing, such as understanding speech. The hearingTable 1 .—Causes of Conductive and SensorineuralHearing ImpairmentsCauses of conductive hearing impairments:External blockage: buildup of wax or presence of a foreignobject in the ear.Perforated eardrum.’ a hole or tear in the eardrum that canoccur as a result of injury, sudden pressure change, or in-fection.Genetic and congenital abnormalities.’ malfunction and/ormalformation of the outer and/or middle ear that can oc-cur in connection with hereditary disease or as a result ofillness or injury before or at the time of birth.Otitis media.’ middle ear infection with fluid accumulation.Otosclerosis: hereditary disease process resulting in over-growth of a small bone in the middle ear which interfereswith sound conduction.Causes of sensorineural hearing impairment:Prenatal and birth-related causes: infections such as rubel-la contracted by expectant mothers, drugs taken duringpregnancy, or difficult labor and delivery.Hereditary causes: a variety of disorders that damage thecochlea or higher nerve centers and are usually presentat birth; the gradual loss of hair cells in the cochlea thatbegins as young as the twenties and thirties in some in-dividuals and may be caused by heredity.Viral and bacteria/ infections: infections such as mumps, spi-nal meningitis, and encephalitis.Trauma: a severe blow to the head, an accident, or a strokeor brain hemorrhage that affect the ear, nerve pathways,and auditory brain centers.Tumors: tumors called acoustic neuromas that invade theeighth nerve.Noise: exposure to loud sounds that irreparably damage thehair cells.Cardiovascular conditions: hypertension, heart disease, orother vascular problems that alter blood flow to the innerear.Ototoxic drugs: aspirin, some antibiotics, diuretics, and cer-tain powerful anticancer drugs that damage the hair cellsor other vital parts of the inner ear.Meniere’s disease: a disorder characterized by fluctuatinghearing loss, dizziness, and tinnitus; possible causes in-clude aIlergy, hypothyroidism, diabetes, and syphilis.SOURCE: NINCDS, 1982 (124),11
  19. 19. 12impaired person may hear the words but not makeany sense out of them. Some words are difficultto interpret, almost as if the person were listen-ing to a foreign language. This kind of hearing im-pairment can be caused by disorders of the audi-tory pathways in the brain. With aging, the speedof nerve impulses may slow or the brain may losethe ability to interpret words that come at a rapidpace.Tinnitus is a condition that often accompanieshearing loss. It is a ringing, buzzing, or hissing inthe ears or head that can be continuous or inter-mittent. The causes of tinnitus are not well un-derstood but can include obstructions in the outerear, perforation of the eardrum, middle ear infec-tion, repeated exposure to loud noise, trauma, andsome medications,Presbycusis is the term most often used to de-scribe hearing impairment in elderly people. Theword presbycusis means “old hearing. ” It is usu-ally defined as a sensorineural loss caused bychanges in the inner ear, but some experts includemiddle ear changes associated with aging in thedefinition (124) and others emphasize the impactof changes in the eighth cranial nerve and audi-tory brain center (54).The diagnosis of presbycusis is used for hear-ing impairment associated with a variety of sen-sory, neural, metabolic, mechanical, and vascu-lar changes seen in elderly people. Yet little isknown about the underlying causes of presbycu-sis and the term is sometimes used when no spe-cific cause of the condition can be identified.Conditions that are frequently diagnosed as pres-bycusis include gradual loss of hair cells in the coch-lea and fibrous changes in the small blood vesselsthat supply the cochlea.1Some researchers believethat these changes are caused primarily by envi-ronmental factors and disease while others believethey are primarily a result of normal aging (125).However, not all elderly individuals are affectedby presbycusis, and some people over 90 retainacute hearing.The diagnosis of presbycusis is sometimes givenmistakenly when a specific cause of the hearingIThe cochlea is dependent on a single artery for blood supply,making hearing very susceptible to damage as a result of cardiovas-cular disease [73),impairment could be identified and possiblytreated (73). For example, wax buildup in the outerear frequently causes hearing impairment inelderly people. If presbycusis is diagnosed, the realproblem—ear wax—might be missed and go un-treated.The term presbycusis can be confusing becauseit is used to describe three situations: 1) treatableconditions caused by disease, 2) conditions causedby disease for which no treatment is known, and3) conditions believed to result from normal aging,For health care professionals, elderly people, andtheir families, a diagnosis of presbycusis may mis-takenly imply that nothing can be done for thepatient. Greater attention to isolating the cause ofa person’s hearing loss can help ensure promptand effective treatment in some cases. In general,however, more research is needed to describe theunderlying pathologies that cause presbycusis andto differentiate between treatable and untreatablecauses of these conditions.To develop a more complete understanding ofhearing loss associated with aging, we must im-prove our knowledge about the basic mechanismsof hearing in the normal ear. While the normalfunctioning of the outer and middle ear is rela-tively well understood, the structural and biochem-ical mechanisms of the inner ear and auditory braincenters are less well understood. The cochlea, apea-sized organ with more than a million movingparts, is one of the most complex mechanical struc-tures in the human body. Only within the past dec-ade have methods been developed to study thistiny structure. Research on the molecular struc-ture and mechanical properties of hair cells in thecochlea and the biochemical processes by whichsound vibrations are converted to neural impulseshas significantly increased our understanding ofthe basic mechanisms of hearing (53). But little isknown about how the damaged ear processessound (88).Lack of communication among researchers inthis field has been a problem but recent researchdevelopments have stimulated increased inter-action. A national conference on auditory bio-chemistry held in 1984 brought many prominentresearchers together for the first time and par-ticipants hope that this process will be repeatedregularly (30).
  20. 20. 13MEASURING HEARING IMPAIRMENTHearing impairment is measured by two meth-ods: interviews and audiometric tests. Definitionsof the levels of impairment reflect these two meth-ods. The interviewrmethod relies on self -reportedhearing loss and the resulting statistics are pre-sented in categories such as: “no trouble hearing, ”‘(can hear words spoken in a normal voice, ” ‘(canhear words shouted across a room,” and “at bestcan hear words shouted in ear” (119). Audiomet-ric tests measure an individual’s response to soundsof varying intensity or loudness, and level of im-pairment is reported in terms of the weakest soundthe individual can hear. Intensity of sound is meas-ured in decibels; zone scale used to define levelof impairment is illustrated in table 2.The level of hearing impairment that is consid-ered significant varies for different surveys, re-search projects, and clinical applications. Hearingspecialists and researchers continue to debate themost appropriate level to call significant for spe-cific applications.3Different surveys show different prevalencefigures in part because they select different levels‘The dccihel scale is a logarithmic Sral(> (hased on poh~rers of 1())that nleasLlrPs intensit~ of sound or loudness. A sm~ll inf’r~ase indecilwls ((IB) represents a large increase in loudness. For example,a s o u n d at 40 dB is 1() t imf?s as bLld as a S{)und at 30 dB and 100times as loud as a sound at 20 dkt3’I’h is drhate is N31(’t’illlt to scrfwning pro~r:irns and iclent ifirationof patients liho need tre:itment as discussed in rh. 4.Table 2.— Hearing Loss in Decibels Related toApproximate Degree of ImpairmentHearing loss in decibels (dB) Degree of impairmento to 20 dB . . . . . . . . . . . . . . . . . . . . . . Normal20 to 40 dB . . . . . . . . . . . . . . . . . . . . . Mild40 to 55 dB . . . . . . . . . . . . . . . . . . . . . Moderate55 to 70 dB . . . . . . . . . . . . . . . . . . . . . Moderately severe70 to 90 dB . . . . . . . . . . . . . . . . . . . . . Severe>90 dB . . . . . . . . . . . . . . . . . . . . . . . . Profound deafnessSOURCE Knauf, 1978 (64).of impairment as significant. Reported prevalencealso varies depending on whether the interviewor audiometric testing method is used. Prevalencefigures based on interviews tend to underestimatethe frequency of hearing impairment becausemany people, particularly elderly people, are notaware of their hearing loss or may deny or mini-mize its severity in an interview. Some experts be-lieve that audiometric testing provides more ac-curate measurement but prevalence figures basedon both methods are widely cited in the literature(10).Four types of audiometric tests are commonlyused to measure hearing loss: 1) pure tone air con-duction, 2) bone conduction, 3) speech reception,and 4) speech discrimination. Pure tone air andbone conduction tests measure hearing loss at spe-cific frequency levels. Hearing loss varies greatlyaccording to frequency, especially in elderly peo-ple, and information about hearing deficits at spe-cific frequencies is important for diagnosis, treat-ment, and research. The prevalence of hearing lossbased on audiometric tests varies according to: 1)the sound frequency used; 2) the decibel level atwhich hearing impairment is recognized for thatparticular survey, called the fence; 3) whether oneor both ears are tested; and 4) whether data arereported for the right or left ear, the better ear,the worse ear, or an average.Some individuals are able to hear the pure tonesused in air and bone conduction tests but havedifficulty understanding speech because of prob-lems in auditory discrimination. This condition,called dysacusis, is widespread among hearing im-paired elderly people. Pure tone air and bone con-duction tests underestimate the extent of dysacu-sis (69) and, as a result, prevalence estimates basedon pure tone air and bone conduction tests areusually lower than those based on speech recep-tion and speech discrimination tests (41).
  21. 21. 14PREVALENCEThe prevalence of hearing impairment varies byage, sex, race, income, and institutional status.prevalence estimates also vary depending onwhether they are based on interview or audiomet-ric testing.4There is ongoing debate about the ac-curacy of interview and audiometric tests for meas-uring hearing impairment and about the level ofhearing loss that constitutes significant disability.These debates are relevant to understandingwhether prevalence estimates are valid.The data in the following discussions reflect ourbest understanding of the nationwide prevalenceof hearing impairment. However, the generaliza-tions may not apply in certain geographic areas.For example, chronic ear infections are commonamong certain ethnic groups in Alaska and Indiansin some Southwestern States and this increasesthe prevalence of hearing impairment in thoseareas. Similarly, in areas where high-noise indus-tries are concentrated, hearing loss is more com-mon among persons of working age and older (10).AgeAccording to the 1977 National Health InterviewSurvey (NHIS), about 8 percent of the civilian,noninstitutionalized population experienced somedegree of chronic hearing impairment. Prevalencerises from about 1 percent of those under age 17to more than 38 percent of those over 75 (see fig-ure 2).4Prevalence figures based on interviews come from the 1977 Na-tional Health Interview Survey (NHIS), conducted by the NationalCenter for Health Statistics (NCHS). NHIS is an annual nationwidesurvey. Respondents are asked about acute and chronic health con-ditions of all members of the household. In 1977, a special supple-ment to the NHIS focused on hearing impairment. NHIS data are be-lieved to underestimate prevalence because some people deny orare unaware of their hearing impairments or may not consider theirhearing loss a problem and because NHIS interviews are usually con-ducted with only one member of the household, who may not beaware of or report hearing impairments of other household members.Prevalence figures based on audiometric testing come from theHealth and Nutrition Examination Surveys (HANES), conducted from1971 to 1975 by NCHS. A random sample of aduhs aged 25 to 74in the civilian, noninstitutionalized population was tested using puretone air and bone conduction tests at 4 frequency levels (500, 1,000,2,000, and 4,oOO Hertz) and a speech reception test. Air and boneconduction tests were reported for the right ear only; this lowersprevalence estimates because those with unilateral hearing loss inthe left ear are not included.Both NHIS and HANES underestimate overall prevalence in theelderly population because the institutionalized elderly, who havevery high prevalence, are not included.Figure 2.—Prevalence of Hearing Impairment,Including Tinnitus, in the Civilian,Noninstitutionalized Population, United States,197712 ”/0?— 80/04 %1 %I240/,All ages Under 17 17-44 45-64 65-7439%Iand overA g eSOURCE: NCHS, 1981 (120).Audiometric surveys also show significant in-creases in hearing impairment with age and theyindicate a higher overall prevalence than interviewsurveys (41, 51). For example, one national audio-metric survey showed that almost 30 percent ofindividuals between 65 and 74 and 48 percent ofthose between 75 and 79 had impaired hearingfor understanding speech (69).Audiometric data show that hearing loss isgreater for high frequency than for low frequencysounds for all age groups. As figure 3 indicates,hearing impairment at high frequencies is verycommon among elderly people.While most speech is in the range of 500 to 2,000H Z )5sounds such as S, th, k, and f are heard athigher frequencies. Elderly individuals with hear-ing impairments at 4,000 Hz (i.e., almost 60 per-cent of all elderly people) are often unable to hearthese sounds and this interferes with their under-standing of normal speech.‘Frequency is measured in vibrations or cycles per second, calledHertz (Hz).
  22. 22. 15Figure 3.— Prevalence of Hearing Impairment Among Adults by Frequency of Tone, United States, 1971-75°I500 Hz25-341 , 0 0 0 H z1 ~ 1 2 , 0 0 0 H z4 , 0 0 0 H z1 7 %0 10 20 30 40 50 60 70Percent hearing impairedaThese data are based on air condition tests, Figures include individuals who were able to hear the tones at 31 decibels or more at least 50 percent Of the time.SOURCE: NCHS, 1960 (1 16).GenderInterview surveys indicate that elderly men havea higher prevalence of hearing impairment thanelderly women. The 1977 NHIS found that amongpeople 65 to 74, about 29 percent of men reportedhearing impairments compared to only 20 percentof women. Among those 75 and over, 44 percentof men but only 35 percent of women reportedhearing impairments (121). Some experts suggestthat these different rates are the result of lifelongexposure to loud noise while hunting, serving inthe military, or working in farm and factory oc-cupations (10, 129).Longitudinal studies indicate that men andwomen aged 50 to 80 experience hearing loss inthe same frequency range, but hearing loss in-creases more rapidly in men than in women. Af-ter age 80, these differences in hearing impairmentbetween men and women become indistinguish-able (54, 123).Audiometric data show much higher prevalenceof high frequency hearing impairment for elderlymen than for elderly women, but elderly womenhave similar or slightly higher prevalence at lowfrequencies (54). For example, air conduction testsused in the Health and Nutrition Examination Sur-vey (HANES) showed that 78 percent of the menfrom age 65 to 74 had hearing loss at 4,000 Hz,compared to only 46 percent of the women in thatage group. In contrast, at 500 Hz about 12 percentof elderly men and 18 percent of elderly womenhad hearing loss, while at 1)000 Hz about 18 per-cent of elderly men and 21 percent of elderlywomen had hearing loss.6Bone conduction testsproduced similar findings (116). The reason forthis variation in prevalence for men and womenat different frequencies is not known.RaceThe 1977 NHIS indicated a substantially lowerprevalence of hearing impairment among non-whites of all ages than among their white coun-terparts (see table 3).Audiometric data show a more complex rela-tionship between race and hearing impairment,HANES data indicate that elderly nonwhites have6Figures include individuals who were able to hear the tones at31 dB or more at least 50 percent of the time,
  23. 23. 16Table 3.—Prevalence of Hearing Impairment,Including Tinnitus, in the Civilian, NoninstitutionalizedPopulation, by Race and Selected Age Groups,United States, 1977RaceAge White All otherUnder 17 years . . . . . . . . . . . . . . . . . . . . . . . 1 % 1 %17 to 44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 345 to 64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 865 to 74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1875 and over . . . . . . . . . . . . . . . . . . . . . . . . . . 39 31SOURCE:NCHS, 1981 (120)a lower prevalence of severe hearing impairmentsthan elderly whites, but a higher prevalence ofmoderate hearing impairments.7This distinctionis true for pure tone air conduction measures at500, 1,000,2,000, and 4,000 Hz. On speech recep-tion tests elderly nonwhites had a higher preva-lence of hearing impairment at all levels of sever-ity except profound deafness (116). The differencebetween these results and data from interview sur-veys suggest that elderly nonwhites may be lesslikely than elderly whites to report hearing im-pairment in an interview.IncomeIn general, persons with low family income havea higher rate of hearing impairment at all ages thantheir wealthier counterparts. For example, the1977 NHIS found that the rate of impairment forpersons aged 65 to 74 with annual family incomesbelow $3,000 was about 30 percent. For the sameage group with incomes in excess of $15)000, therate was about 20 percent (121). With only minorvariation, this inverse relationship between incomeand hearing loss is sustained for all age catego-ries. Although the reasons for this relationship arenot known, it may be because low income peoplehave poorer general health, poor primary healthcare, and greater exposure to environmental noise7For this comparison, hearing impairment above 50 dB is consid-ered severe, while impairment from 31 dB to 50 dB is consideredmoderate.and this results in higher prevalence of hearingimpairment (10, 42).InstitutionalizationThe prevalence of hearing loss among institu-tionalized elderly people is greater than amongnoninstitutionalized elderly people. One surveyin a Veterans Administration nursing home foundthat 90 percent of the residents had hearing im-pairments (132). A review of research on hearingloss among nursing home residents found preva-lence estimates ranging from 48 to 82 percent (98).The variation among these findings is attributedto: different methods of measuring hearing loss,the types of nursing homes studied, characteris-tics of the selected population, lack of uniforminterpretation of “hearing loss)” and lack of infor-mation about threshold sensitivity at individual fre-quencies.A study of hearing impairment in a nursing homein Canada pointed out the inadequacy of selfreports for assessing hearing impairment in thistype of setting (22). Residents were interviewedabout their hearing ability and given audiometrictests. Fifty percent of the residents acknowledgeda hearing loss in interviews, but audiometric test-ing showed that 75 percent actually had hearingimpairments. Eight percent of the residents re-ported hearing loss when there was no audiomet-ric evidence of impairment, while 33 percent re-ported normal hearing but actually had clinicallysignificant loss. Audiometric testing should be aroutine procedure for elderly people admitted tonursing homes since hearing loss, including un-recognized loss, can affect a person’s ability to func-tion normally.Prevalence of TinnitusThe prevalence of tinnitus increases with age(see figure 4) and more women than men reporttinnitus (69).
  24. 24. 17Figure 4.— Prevalence of Tinnitus, by Severity andSelected Age Groups, United States, 1960-62a50 I40 severe0 L33—38———4118-24 25-34 35-44 45-54 55-64 65-74 75-79AgeaPercentage figures rounded to nearest whole number.SOURCE: Leske, 1981 (69).THE IMPACT OF HEARING IMPAIRMENTClinical ImpactHearing impairment lessens a person’s ability tohear environmental sound without amplification.In some cases it also diminishes the ability to dis-criminate between sounds even with amplifica-tion. This condition is common among hearing im-paired elderly people and results in the complaint,“I can hear you, but I can’t understand you” (54,89). Some research indicates that auditory discrimi-nation is a problem even for some elderly peoplewith normal hearing as measured by pure toneaudiometric tests. This is less often true of young-er people with normal hearing measured in thesame way (63).Loss of the ability to hear high-frequency soundsis characteristic of hearing impairment in manyelderly people. At birth the human being is ableto hear sounds as high as 30,000 Hz, but each yearof life results in some loss. By the teens, many in-dividuals can hear only up to 20,000 Hz, and byold age many people cannot hear sounds at 4,000Hz or even 2,000 Hz, the level of some speechsounds (32).Elderly people with hearing impairment usuallyhave diminished ability to hear low-intensitysounds, but their ability to hear very loud or high-intensity sounds can remain unchanged. This canmake it uncomfortable to use hearing devices thatamplify all sounds uniformly because relativelyloud sounds that are amplified then become in-tolerably loud (89).Another common characteristic of hearing im-pairment in elderly people is an inability to tuneout background noise. Many elderly people experi-ence difficulty hearing in a noisy environment be-cause they cannot separate speech from back-ground noise (54, 82). Although available data arenot conclusive, studies suggest that elderly peo-ple have more difficulty hearing in a noisy envi-ronment than younger people with comparablehearing ability. Furthermore, even elderly indi-viduals with normal hearing ability, measured byaudiometric tests, can experience problems withbackground noise (31,44). Sound reverberationsin large rooms such as auditoriums and churchesalso interfere with speech perception among manyelderly people.aIn the normal ear, the efferent system is a sys-tem of complex neural mechanisms that act to con-%h. 3 discusses the implications of these findings for hearing aiddesign, the use of assistitw listening de~’ices, and eniironmentaf de-sign technologies. Implications for screening programs and iden-tification of people ~tho need treatment are discussed in ch. 4,
  25. 25. 18trol discrimination of sound, detection of soundsignals in noise, and localization of sound. Littleis known about how this system inhibits responseto some auditory signals and tunes out unwantedsound. Further, it is not known how the efferentsystem changes with age and whether suchchanges are part of why elderly people have diffi-culty understanding speech in noisy environments.Continued research on the mechanisms of selec-tive inhibition could help increase our understand-ing of hearing impairment in the elderly (30).psychosocial ImpactHearing impairment causes psychological andsocial difficulties because it interferes with a per-son’s ability to communicate effectively. Commu-nication plays an essential role in maintaining rela-tionships and the quality of life, and hearing lossdeprives not only the individual, but also familyand friends, of easy communication. Repeated in-stances of unheard or incorrectly heard commu-nication are frustrating for the individual andeveryone he converses with and may cause allthose involved to initiate conversation less fre-quently. When these frustrating situations occurover prolonged periods, family relationships canbe severely strained. Hearing loss also can affecta person ability to speak clearly because his ownvoice sounds distorted, and this can add anotherimpediment to communication.Hearing loss limits a person’s ability to enjoymany forms of entertainment, such as television,radio, music and theater, and as a result he maywithdraw from them. Similarly, some hearing im-paired people stop going to church and socialgatherings because they cannot hear well enoughto enjoy these activities (32, 54). Hearing impair-ment also limits access to information that is nor-mally available through personal communication,television, radio, and telephone. Elderly peoplewho have both hearing and visual impairmentsare even more severely limited in their access toinformation.Aging can bring many kinds of losses: loss of in-come and decreased sense of usefulness associ-ated with retirement; loss of relationships due tothe death of spouse, siblings, and friends or dueto a physical move from a familiar home or com -munity; and diminished health, energy, and mo-bility. While most elderly people cope well withthese losses, hearing impairment can hinder thecoping process by interfering with the person’sability to become involved in new activities, formnew relationships, and arrange for needed serv-ices (10).For some people, hearing impairment can leadto withdrawal, social isolation, and depressioncaused by lack of interpersonal communicationand contact. One British study found a significantrelationship between depression and hearing im-pairment among community dwelling elderly peo-ple (51). Another study, however, found no corre-lation between hearing impairment and eitherdepression or social interaction (112). The re-searchers suggest that the subjects in the latterstudy may not be typical of the elderly populationbecause of their general good health, economicsecurity, and high level of education. Further re-search is needed to clarify the relationship betweenthese variables.Clinical observation suggests that there is a rela-tionship between hearing impairment and psy-chopathology in some individuals. Particularlywhen hearing impairment occurs gradually, as itoften does in later life, deaf and hard-of-hearingindividuals sometimes develop delusions of perse-cution and other paranoid reactions. These symp-toms may occur because the older person is notaware of his hearing impairment—he notices thatothers seem to be talking in his presence but tooquietly for him to hear or that they are laughingabout something he cannot hear. He becomes sus-picious and may accuse them of excluding him de-liberately. When they deny these accusations, hemay become more suspicious.Research has demonstrated this relationship be-tween hearing impairment and paranoid symp-toms (139). College students were hypnotized toinduce temporary hearing impairment and thenasked to work with others on a joint project. Thesesubjects tended to develop symptoms of paranoia,including suspiciousness, grandiosity, irritability,and judgmental attitudes.Some clinicians and long-term care providershave suggested that hearing impairment can causeor exacerbate mental deterioration in old age (10).
  26. 26. 19One study found a significant relationship betweenhearing impairment and dementia (51). The rela-tionship did not hold up, however, when age wascontrolled, indicating that while both hearing im-pairment and dementia are associated with advanc-ing age, they are not otherwise correlated. Anotherstudy showed that hearing impaired individualsdo as well as individuals with no hearing problemson nonverbal tests of cognition but less well onverbal tests (112). It is not known whether theseresults occur because the hearing impaired indi-viduals do not hear the questions on verbal testsclearly or whether some types of hearing impair-ment interfere with cognitive processes for en-coding and recalling verbal messages.Changes in brain function associated with agingcan affect hearing, according to a report preparedby the Working Group on Speech Understandingand Aging of the National Academy of Sciences.The report, to be published in 1986, indicates thatphysiological changes in the brain that affect over-all brain function (not only the auditory braincenters) can result in slowed response to auditorystimuli (113). Continued research on the relation-ship between cognitive change and hearing lossis needed.Perhaps more important than any actual rela-tionship between hearing impairment and men-tal deterioration is a widespread assumption insociety that elderly persons who are hearing im-paired are also confused (30, 112, 124). A strongtendency exists to stereotype elderly people assenile (95) and the additional factor of a hearingloss increases stereotyping. In a study conductedin an acute care hospital, health care professionalsdescribed their impatience with elderly personswith hearing losses (9). Several respondents saidthe method they used in interactions was to“scream at them. ” This behavior was consideredacceptable since the patients were old “and prob-ably senile, too. ”Other negative attitudes about individuals withhearing impairments are also widely held. Peopleseem to be more sympathetic to visible impair-ments and may be more sympathetic to blind peo-ple than to those with hearing impairments. More-over, there is an unfortunate tendency to blamethe hearing impaired person for his or her disabil-ity, especially if the person is also old. This ten-dency may partially explain the sense of shamethat many hearing impaired people feel (82). Fi-nally there is a common belief among health careproviders, as well as among the general public,that hearing loss in elderly people is not treatable(lo).A study comparing hearing impaired elderly peo-ple who did not seek treatment with those whodid seek treatment identified two factors that af-fected whether people sought help: 1) the sever-ity of the impairment, and 2) the onset of hearingimpairment before retirement age. Both elderlyindividuals and their physicians can have nega-tive attitudes about hearing loss that begins in oldage. This can play an important role in determin-ing which individuals seek treatment (55).Nursing home residents are very likely to havehearing impairments that can be particularlydevastating for several reasons. The move to anursing home requires adjustment to a new envi-ronment, new people, and new daily routines.Hearing impairment interferes with the individ-ual’s ability to develop relationships with staff andother patients and to fully understand the dailyschedule. One regular visitor to a nursing homereports a comment that is heard all too often withregard to hearing impaired residents, “Don’t bothertalking to her, she can’t hear you” (14).Some hearing impaired nursing home residentshave mobility impairments that interfere with theirability to interact with others and other sensoryimpairments, such as vision and speech deficits,that further reduce their ability to socialize. Thesemultiple impairments compound the isolation oftenassociated with severe hearing loss. Finally, manynursing home residents have irreversible mentalimpairments caused by strokes, primary degener-ative dementias such as Alzheimer’s disease, orother disease conditions. In this context, it is easyfor nursing home employees to assume that hear-ing impaired residents who do not answer ques-tions correctly and do not seem to understand thedaily routine are also mentally impaired. The im-pact of this assumption on the hearing impairedresident’s quality of life can be very severe.Denial of Hearing ImpairmentMany elderly people deny they have a hearingproblem despite substantial evidence to the con-
  27. 27. 20trary. Many authors have discussed the problemsof denial and refusal to seek treatment (76), butlittle attention has been given to the underlyingreasons for it. Elderly people who deny or avoidconfronting a hearing loss are not doing so in avacuum. Negative social attitudes about hearingimpairment and growing old encourage denial.Hearing impairment is not visible, and invisibilityfacilitates denial. In addition, hearing impairmentin elderly people often has a very gradual onsetthat can make it difficult to recognize.For elderly persons with one or more life-threat-ening illness, hearing impairment may seem in-significant in comparison. The onset of depression,withdrawal, paranoia, and other mental healthproblems associated with hearing impairment isslow and insidious and may seem unrelated to thehearing loss. An elderly person’s inability to re-ceive aural cues can lead to accidents, though thecauses may seem ambiguous. Likewise, difficul-ties in communication and social relationships maynot be attributed to hearing loss, even when theloss is acknowledged. As a result, hearing impair-ment often is mistakenly seen as unimportant byelderly people, their families, and health careproviders (10). This denial of the importance ofhearing impairment and our failure to recognizeits full impact on independent functioning are clearobstacles to effective treatment.DEAFNESSOnly a small percentage of elderly people aredeaf. There is no consensus about the exact prev-alence of deafness, in part because of variationin the method used to measure hearing impair-ment and the level of impairment that is definedas deafness. However, estimates using audiometrictests indicate that about 2 to 4 percent of all el-derly people are deaf (116, 119). Among peopleover 75, prevalence increases somewhat, and ifpeople with severe hearing impairments are in-cluded, prevalence increases significantly.For practical purposes elderly deaf people canbe divided into three groups: 1) those who becamedeaf very early in life before language was ac-quired, 2) those who became deaf during early ormiddle life after language was acquired, and 3)those who became deaf during later life. Peoplewho have been deaf since childhood have usuallylearned to use sign language and have deaf andnondeaf friends and associates with whom theycan communicate using sign language.gSince theirmethod of communication is manual, their abilityto communicate usually does not diminish withage. Some people who became deaf in early or mid-dle life use speechreading as their preferred modeof communication. Visual impairments acquired‘1’his network of informal relationships is often wfcwcxi to asthr “deaf communit~’.”late in life can interfere wispeechreading techniques.th their ability to useIndividuals who become deaf late in life facedifferent problems. Sign language is an entirelynew and complex system of communication thatthey must learn if they are to interact with otherdeaf people who use sign language. Yet their rela-tives and lifelong friends seldom know sign lan-guage. The result can be extreme social isolation.People who are deaf and people with partial hear-ing loss are similar in some ways and very differ-ent in others. Both groups can benefit from in-creased awareness of their communicationproblems among their families, friends, health careand social service providers, and others who in-teract with them. Yet the devices and hearing serv-ices that are most effective for each group aredifferent. For example, sign language and telecom-munication devices that rely on visual messages,such as the telecommunication devices for the deaf(TDDs) described in chapter 3, are most effectivefor deaf people. In contrast, hearing aids, assis-tive listening devices, and telephone amplifiers aremore appropriate for those with partial hearingloss.In the past, hearing research and many hearingservices have focused on deaf and very seriouslyhearing impaired people, and less emphasis has
  28. 28. been placed on partial hearing loss (10). When deafpeople and those with partial hearing loss are com-bined into a single category-’’the hearing im-paired’’ -at least 16 million people are included.Yet this large number is sometimes used to justifyfunding for research programs and hearing serv-ices focused primarily on the deaf—a group of21about 2 million people. Self-help groups for hard-of-hearing people have pointed out this discrep-ancy (109) and funding agencies and hearing re-search centers are slowly readjusting their re-search and service priorities to encompass the verylarge proportion of hearing impaired people whoare not deaf.
  29. 29. Treatment of Hearing ImpairmentChapter 3
  30. 30. Chapter 3Treatment of Hearing ImpairmentThe options available for treating hearing im-pairment in elderly people are generally the sameas for younger people. However, the suitability andeffectiveness of various treatments differ consider-ably among age groups because of the type of hear-ing loss most frequently encountered and becauseof other physical, psychological, and social char-acteristics of each group (10).Preventing hearing impairment is an obviousfirst approach. Even if hearing impairment can-not be completely avoided, preventive measurescan slow the rate of deterioration or reduce theultimate severity of the impairment. A second ap-proach is medical and surgical treatment. Whilethese treatments are effective for some types ofhearing impairment, the types of hearing prob-lems that are most common in elderly people arenot presently treatable with medical or surgicalmethods. Thus alternatives are needed. These gen-erally do not change the underlying hearing lossbut instead help compensate for hearing loss andmaintain adequate communication. They includethe use of hearing aids, assistive listening devices,telecommunication devices, signaling and alarmdevices, and environmental design technologies.In addition, aural rehabilitation services can helphearing impaired people communicate more suc-cessfully with or without the use of amplificationdevices.PREVENTIONSome causespeople are notof hearing impairment in elderlywell enough understood to alloweffective preventive measures. For example, die-tary factors and circulatory changes have beenimplicated as accelerators of deterioration in theauditory system. Yet the specific relationship ofthese factors to hearing loss is not known, and fur-ther research is needed before preventive strate-gies can be developed (10).other causes of hearing impairment are well un-derstood and often preventable; these include un-treated ear infections, exposure to loud noise, andsome medications. Untreated or inadequatelytreated ear infections at any time in life can causeconductive hearing loss, though it may not be im-mediately disabling. In old age, however, as sensori-neural loss further reduces hearing acuity, seri-ous disability may develop. Thus better health carethroughout life could prevent some hearing im-pairments in old age (10).Exposure to loud noise at any age can cause ir-reversible sensorineural damage and significanthearing loss. Airplanes, motorcycles, heavy traf-fic, farm and industrial machinery, gunfire, andloud music are sources of noise that can perma-nently damage hearing. Other sources of loud noisehave also been identified. For example, the Amer-ican Academy of Otolaryngology-Head and NeckSurgery has recently warned that some types ofcordless telephones can cause hearing loss becausethe phones continue to ring at a high decibel levelafter being answered until a switch is flipped tothe ‘(talk” position. Seven million of these cordlessphones were estimated to have been sold in 1984(2).The popularity of loud rock music, along witha rise in other environmental noise, creates a se-vere threat to the auditory acuity of young peo-ple. A 1968 study of hearing impairment amongstudents in Knoxville, Tennessee, showed that 4percent of sixth graders had hearing loss at highfrequencies. This proportion increased to 11 per-cent of ninth graders and 33 percent of freshmenat the University of Tennessee. A year later, a sim-ilar study showed that more than 60 percent ofthe next freshman class had some hearing loss (70).As these individuals grow older, their noise-in-duced hearing loss may be exacerbated by the au-ditory changes associated with aging.Self Help for Hard of Hearing People, one of theself -help groups for hearing impaired people, has25
  31. 31. 26developed a “Quiet School Program” to provideinformation and educational materials to schooladministrators, teachers, students, and parentsabout the relationship between loud noise andhearing loss. The materials include colorful postersand a device that flashes a warning light when noisein the school cafeteria reaches a dangerous level(101).The increased use of portable radios and tapeplayers with earphones may cause a greater prev-alence of noise-induced hearing loss. A study inNew York City found many listeners playing theirportable radios at 100 decibels, the equivalent ofa car horn 3 feet away (65). A recent British re-port concluded, however, that portable radios andtapeplayers are a less serious threat to hearing thanare other sources of loud noise such as industrialmachinery and gunfire (38).Federal legislation to control noise includes theOccupational Safety and Health Act of 1970 andthe Noise Control Act of 1972. Federal regulationsdefine the amount of time that workers may beexposed to noise of a given intensity. Noise con-trol procedures have been implemented in someindustries. In addition, some local governmentshave enacted noise control legislation and viola-tors are being prosecuted (111). These efforts even-tually may reduce the prevalence and severity ofnoise-induced hearing loss. Many incidents of ex-posure to loud noise, however, are not within gov-ernment regulatory control. Increased public edu-cation is needed to alert people of all ages to theimpact of loud noise on hearing and the long-termdamage that can result.Some drugs also damage auditory mechanisms.Although not a major cause of hearing impairment,these “ototoxic” drugs must be considered in anydiscussion of prevention. The best known of thesedrugs are the aminoglycosides, a class of antibi-otics that includes streptomycin. These drugs canbe life-saving; unfortunately, they also sometimesdamage hearing (10). Even commonly used, over-the-counter drugs such as aspirin can be ototoxic,although probably only in the high dosages some-times used to treat arthritis. Fortunately, aspirin-induced hearing loss is usually reversible if it isrecognized early and aspirin dosage is reduced (10).ototoxic drugs can create problems in peopleof any age. Nevertheless, diseases that require theiruse are more prevalent in later life. Too little re-search has been done to provide a full understand-ing of the mechanisms of ototoxicity and of theessential chemistry of the agents that may be oto-toxic. Educational efforts have been effective ininforming most physicians of the potential haz-ards of streptomycin, but the ototoxic effects ofother drugs have been less well publicized (10).Hearing loss is a symptom with many possiblecauses and accurate diagnosis can sometimes helpprevent permanent hearing impairment. Yet someelderly people do not receive thorough diagnos-tic evaluation. Symptoms such as sudden onset ofhearing impairment and unilateral deafness sug-gest a diagnosis other than presbycusis, and med-ical evaluation of patients with these symptomscan sometimes lead to effective treatment (73).
  32. 32. 27MEDICAL AND SURGICAL TREATMENTMedical and surgical treatment can resolve con-ductive hearing losses that originate in the outeror middle ear, but the sensorineural losses thatare most common among the elderly generally can-not be treated with available medical and surgicalmethods. Cochlear implants can alleviate profoundsensorineural hearing loss in some individuals andresearch continues to improve these devices.Treatment of ConductiveHearing ImpairmentsWax buildup in the outer ear is common amongthe elderly and interferes with the passage of soundto the middle ear. Recognizing this problem andremoving the impacted ear wax can improve hear-ing even if there are other auditory deficits.1.Middle ear disease is most common in childhoodbut it also occurs in adulthood and old age. Otitismedia (infection of the middle ear) can be causedby allergies or upper respiratory infection and ef-fective treatment may require medication. Perfo-ration of the eardrum can occur at any age as theresult of middle ear infection or direct trauma.Repair occurs without treatment in some cases,while surgical repair is needed in other cases.Otosclerosis impairs movement of the stapes, asmall bone in the middle ear. The impaired move-ment causes progressive hearing loss. While themost common age of onset is in the third or fourthdecade of life, surgery can be beneficial at any ageand carries only a small risk of complication (27).Treatment of SensorineuralHearing ImpairmentsAlthough most sensorineural losses cannot becorrected through medical or surgical interven-tion, some losses due to tumors, sudden vascularchanges, or fluid pressure changes affecting theinner ear or auditory nerve can be treated. Thesedisorders, however, are relatively infrequent inelderly people (12).IRemOl:Il of impacted ear ~~a.x can tw diffiruit and painful andshould tw (lone L]ndPr ttlc supf’rl is ion 0[ a ph:’s irian.Acoustic TumorsAcoustic tumors can cause sensorineural hear-ing loss, vertigo (dizziness), tinnitus, facial paraly-sis, or numbness. These tumors generally occurduring the third or fourth decade of life but mayalso occur in the sixth and seventh decade (13.5).These tumors can be fatal and surgical removalis a life-saving measure, but it does not usually re-sult in improved hearing.Meniere’s DiseaseSensorineural hearing loss can also result fromMeniere’s disease, the symptoms of which includefluctuating hearing loss, tinnitus, pressure in theears, and vertigo (93). The cause of Meniere’s dis-ease is not known. Treatment with medication isthe first choice, and surgery is used only whenhearing loss or disabling vertigo persists despitedrug therapy. Rates of success with surgery varyfrom 62 to 95 percent, depending on the type ofsurgery performed (92).Cochlear ImplantsThe cochlear implant is an electronic device de-signed to give persons with profound bilateral sen-sorineural hearing loss an improved sense ofsound. Part of the device is surgically implantedin the inner ear and part of it is worn externally(see figure 5). The cochlear implant is intendedto neuroelectrically simulate natural hearing, butfull attainment appears far in the future (10). Thesound produced by these devices has been de-scribed as fluctuating, grating noises and buzzes(88), and users need extensive training to learn tointerpret the sound. Yet implants have improvedspeechreading ability—at least in isolated experi-ments—by giving rudimentary clues to a speakerwords (25). These devices also provide a sense ofthe duration, rhythm, and loudness of sound thatcan be helpful in understanding speech and iden-tifying environmental sounds (8, 71).Cochlear implants hold most promise for deafpeople whose transducing organ in the cochleais ineffective but whose auditory nerve endingsare still responsive to direct stimulation (88). Inthe past 20 years, hundreds of people worldwide
  33. 33. 28Figure 5.—Cochlear Implant in Place$The cochlear implant translates sound into electrical signals, bypass-ing damaged tissues in the inner ear and allowing the brain to receiveauditory information. It works as follows: An external microphone de-tects sound which is translated into electrical impulses by a signalprocessor and then transmitted to an external coil positioned behindthe ear. This coil induces a like signal in another coil implanted in-side the skull. From the internal coil, the signal is carried to an elec-trode in or on the cochlea, stimulating nearby auditory nerve fibersto transmit messages to the brain. This diagram shows the parts ofthe implant designed by William House and his colleagues. Other sys-tems are similar, except that the external coil and microphone maybe worn on a headset and multichannel devices have more electrodes.SOURCE: D. Grady, “Sounds Instead of Silence,” Discover, 1983.have received experimental cochlear implants, andmany of them have been enthusiastic about theresults (71). No statistics are available on the num-ber of elderly persons who have received implantsor their response to them. In 1984, the Food andDrug Administration (FDA) approved one type ofcochlear implant for clinical use in the UnitedStates, a device developed by William House and3M Corp. In 1985, FDA approved a more sophisti-cated implant developed in Australia.Research on cochlear implants continues at theHouse Ear Institute of Los Angeles; the KresgeHearing Research Institute at the University ofMichigan; Stanford University Medical School;University of California, San Francisco; Johns Hop-kins University School of Medicine; and other hear-ing research centers. One focus of research is im-proving the sound processing capabilities of thedevices. Another focus is the development of mul-tichannel devices that are expected to allow morerealistic sound perception for the individual (71).The House implant illustrated in figure 5 is a sin-gle-channel device with a single stimulating elec-trode, and the Australian device mentioned aboveis a single-channel device with 22 stimulating elec-trodes. Four- and eight-channel devices are nowbeing tested and some people report significantimprovement in speech recognition with these de-vices. Researchers believe that with enough chan-nels, the cochlear implant could restore normalhearing. However, the difficulties involved in de-signing a multichannel device and successfullyplacing and maintaining it in the tiny, spiral-shapedcochlea are formidable (71).Cochlear implants can damage remaining nervefibers and other delicate tissues in the patient’sear. As a result, researchers in England, Austria,and Switzerland are working on ‘(extra cochlear ”devices, where the electrode is implanted outsidethe cochlea (45).In its present form the cochlear implant is notappropriate for most elderly people because theyhave partial hearing loss rather than the profounddeafness for which the device is now used. Anec-dotal evidence indicates that some people who havehad implants have been severely disappointed bylimitations on the sounds they are able to hear (128).Cochlear implants are expensive, ranging from$12,000 to $15,000 for preoperative evaluation,surgery, the device, and postoperative auditorytraining (8). In the future, however, as cochlearimplants are improved through research and test -ing they may become an important treatment op-tion for elderly people.HEARING AIDSSince only a small portion of elderly people with the problem are essential. For many years, hear-hearing impairments can benefit from medical or ing aids were the only available option. Recentlysurgical treatment, other approaches to mitigate there has been increased interest in other devices
  34. 34. 29that can help individuals with hearing impairmentsand these devices are discussed later in thischapter.Hearing aids are amplification devices that com-pensate for partial hearing loss. The individualmust have some residual hearing to benefit froma hearing aid. The earliest hearing aids were me-chanical “ear trumpets” that gradually evolved intothe small, more effective, battery-powered tech-nology that is available today.Hearing aids are available in five basic styles: on-the-body, over-the-ear, eyeglass, and two in-the-ear styles (see figure 6). On-the-body aids have areceiver that is attached to clothing or carried ina pocket, Ear-level aids are worn over the ear orfitted into the temple bar of eyeglasses. In-the-earaids include one style that fits into the auricle orouter area of the ear and a smaller device, the ca-nal style aid, that fits almost completely into theear canal.Until recently, the most frequently sold hear-ing aids were over-the-ear aids, but beginning in1983 in-the-ear styles have outsold the other types.In-the-ear aids are popular because of their smallsize, and the canal style aid, which first appearedon the market in 1982, is extremely popular forIOn-the-body typethis reason. Table 4 shows the types of hearingaids sold in 1984. Canal style aids are included inthe “in-the-ear” category. Sales of canal style aidsincreased from less than 1 percent of total hear-ing aids sold in 1982 to 9 percent in 1983, and 22percent in 1984 (23). About 65 percent of peoplewho bought hearing aids in 1984 were fitted forone aid, while about 35 percent were fitted fortwo aids, one for each ear (23).In the past, on-the-body aids could provide moreamplification than other types of aids and weretherefore recommended for people with severehearing impairments. Recent technological ad-vances in the miniaturization of hearing aid com-ponents now make it possible for individuals withsevere hearing impairments to use ear-level aids.Increased miniaturization, however, has raisedconcern about the quality of sound provided, par-Table 4.—Types of Hearing Aids Sold in theUnited States, 1984Type of aid Percent of total salesIn-the-ear . . . . . . . . . . . . . . . . . . . . . . . 60.00/0Over-the-ear . . . . . . . . . . . . . . . . . . . . . 37.0On-the-body . . . . . . . . . . . . . . . . . . . . . 1.5Eyeglass . . . . . . . . . . . . . . . . . . . . . . . . 1.5. -SOURCE: Cranmer, 1965 (23).Figure 6.—Hearing Aid TypesOver-the-ear typeEyeglass typeIn-the-ear typeCopyright 1976 by Consumers Union of United States, Inc., Mount Vernon, N.Y. 10553. Reprinted by permission from CONSUMER REPORTS, June 1976.
  35. 35. 30ticularly with devices as small as canal style aids.Miniaturization of the microphone and speakerelements of hearing aids has been less effectivethan miniaturization of the electronic circuitry,and this can result in sound distortion—a seriousdrawback for elderly people who have difficultywith auditory discrimination (54, 60). While re-search continues to improve the miniaturized com-ponents of hearing aids, some hearing specialistsworry that people may select a small hearing aidthat is not well suited to their needs because ofits cosmetic appeal.Over the years, hearing aids have helped mil-lions of people by maximizing their residual hear-ing and allowing them to function in communica-tion situations that otherwise would have beenimpossible. Yet most people with hearing impair-ments do not use hearing aids. Estimates of thepercentage of hearing impaired people who usehearing aids vary depending on the source of thedata and the figure that is used for overall preva-lence of hearing impairment. A recent analysisusing three different prevalence rates estimatesthat between 8 and 17 percent of all hearing im-paired people use hearing aids (41). A 1984 indus-try survey indicated that of the 16 million peopleof all ages with hearing impairments in the UnitedStates, about 4 million (25 percent) own hearingaids. About 2 million others (12.5 percent of hear-ing impaired people) do not admit to having a hear-ing impairment, and the remaining 10 million (62.5percent) admit to having a hearing impairment butdo not have a hearing aid. Of those who own hear-ing aids, about 14 percent do not use them (49).The majority of hearing aid users are elderly.Table 5 gives the age breakdown of individualswho bought hearing aids between 1983 and 1985.Table 5.—Proportion of Hearing Aid Purchasersby Age, 1983-85Proportion of allAge hearing aid purchasers2 to 39 . . . . . . . . . . . . . . . . . . . . . . . . 8%40 to 49 . . . . . . . . . . . . . . . . . . . . . . . 350 to 59 . . . . . . . . . . . . . . . . . . . . . . . 1160 to 69 . . . . . . . . . . . . . . . . . . . . . . . 3170 to 79 . . . . . . . . . . . . . . . . . . . . . . . 3080 to 89 . . . . . . . . . . . . . . . . . . . . . . .14} 78%90 to 99 . . . . . . . . . . . . . . . . . . . . . . . 3SOURCE: Market Facts, 1985 (75).Elderly people with hearing impairments aremore likely to use hearing aids than younger peo-ple with comparable hearing loss. Data from the1977 National Health Information Survey show thatabout 20 percent of all hearing impaired personsover 65 used a hearing aid, compared to 4 percentof hearing impaired persons age 3 to 44 and 10percent of hearing impaired persons age 45 to 64(118). Among elderly people, hearing aid use in-creased with increasing severity of hearing impair-ment (see table 6).Even though elderly people with hearing impair-ments are more likely to use hearing aids thanyounger people with similar impairments, mosthearing impaired elderly people do not use hear-ing aids. Many reasons for this have been sug-gested. Some elderly people are unaware of theirhearing impairments and therefore do not buy anaid, others reject the use of a hearing aid becausethey associate it with getting old or becoming hand-icapped. Still others believe that their hearing lossis not severe enough to require the use of a hear-ing aid or that hearing aids are not effective forthe kinds of impairments they have. Cost is an ad-ditional deterrent for some people (49).Among those who do buy hearing aids, some arevery satisfied; others are less satisfied; and someare disappointed with the aid. A nationwide sur-vey of people of all ages who purchased hearingaids between 1983 and ,19852asked respondentshow satisfied they were with their hearing abilitywith the current hearing aid. Responses are shownin table 7.Those who answered that they were somewhatdissatisfied (6 percent) or very dissatisfied (4 per-cent) were asked about specific problems they ex-perienced in using the aid. These people identi-fied the following problems (75):q amplification of unwanted noise,‘This survey, commissioned by the Federal Trade Commission(FTC), was designed to produce a representative sample of all U.S.households and to reflect the experiences of all hearing aid pur-chasers nationwide (86). The FTC requested public comment on themethodology of the survey, and no serious problems in survey meth-ods were identified by the time the public record was closed (87).Since then, analysts have pointed out that the survey might be bi-ased because it was a mail survey and because the respondents weremembers of a panel of consumers who had agreed to participatein Market Facts surveys ( 107).