Relationship between audiometric data, hearing difficulties and amplification considerations

1. Relationship between
audiometric data, hearing
difficulties and amplification
considerations

2. • Hearing loss may be categorized along four dimensions: degree,
onset, causation, and time course.
• In terms of degree, hearing loss may be characterized as mild,
moderate, moderate-to-severe, severe, or profound.

3. • Configuration of hearing loss reflects the extent of hearing loss at
each of the audiometric frequencies and provides an overall picture
of hearing sensitivity
• Bilateral versus unilateral
• Symmetrical versus asymmetrical
• Fluctuating versus stable.

4. • Onset of hearing loss : prelingual, perilingual, or postlingual.
• The postlingual distinction may be further divided into four additional
cohorts. These are:
• Prevocational (around the ages 5–17 years)
• Early working age (18–44 years)
• Later working age (45–64 years)
• Retirement age (65 years and older)

5. • Depending on a patient’s membership in a cohort, his or her aural
rehabilitation needs may vary.
• For example, someone who is prevocational may benefit from having
a special amplification system available in the classroom, and the
child’s family may benefit from communication strategies training.

6. • Another person of later working age may require personal
adjustment counselling and even psychosocial support to accept his
or her change in abilities.
• The consequences of not receiving aural rehabilitation will also vary
because of cohort membership

7. • For example, a toddler who incurs hearing loss and who does not
receive an appropriate listening aid will likely experience significant
spoken language delay.
• An older man who incurs hearing loss will maintain normal speech
and language, but may withdraw and isolate from family and friends
and experience depression

8. Listening difficulties

9. • Nonetheless, audiometric data and performance scores do not fully
reflect the patient’s rehabilitation needs in real-life situations
• Daily life situations represent a broad range of different acoustical
environments, consisting of
• Varying speech levels,
• Fluctuating noises,
• Reverberation,
• that are not well covered by the available diagnostic test methods

10. • For instance, average values derived from pure-tone audiometry
• Have a low predictability for the subjective difficulty experienced
during daily listening situations (Kramer, Kapteyn, Festen, & Tobi,
1995).
• In addition, in daily life, speech is often heard among a variety of
sounds and noisy backgrounds

11. • That can make communication even more challenging (Hällgren et al.
2005).
• Previous research suggests that hearing-impaired listeners suffer
more from such adverse conditions
• In terms of speech perception performance as compared with
normal-hearing listeners (Hagerman 1984; Plomp 1986; Hopkins et al.
2005).

12. • It has been suggested that keeping up with the processing of ongoing
auditory streams increases the cognitive load imposed by the
listening task (Shinn-Cunningham & Best 2008).
• As a result, hearing-impaired listeners expend extra effort to achieve
successful speech perception (McCoy et al. 2005; Rönnberg et al.
2013).

13. • Increased listening effort due to impaired hearing can cause adverse
psychosocial consequences,
• such as increased levels of mental distress and fatigue (Stephens &
Hétu 1991; Kramer et al. 1997, 2006),
• lack of energy and stress-related sick leave from work (Gatehouse &
Gordon 1990; Kramer et al. 2006; Edwards 2007; Hornsby 2013a, b).

14. • Nachtegaal et al. (2009) found a positive association between hearing
thresholds and the need for recovery after a working day.
• In addition, hearing impairment can dramatically alter peoples’ social
interactions and quality of life
• Due to withdrawal from leisure and social roles (Weinstein & Ventry
1982; Demorest & Erdman 1986; Strawbridge et al. 2000

15. • Individuals with adult onset hearing loss experience varying levels of
hearing handicap.
• To date, primary assessment of this handicap has been made through
either arithmetic calculation or self-report
• Over several decades, a number of arithmetic formulas applied to
audiometric data have been proposed

16. • Available formulas include those of the
• American Medical Association (AMA),
• American Academy of Otolaryngology (AAO),’
• ASHA Task Force on the Definition of Hearing Handicap,’
• Committee on Hearing Bioacoustics and Biomechanics (CHABA),”

18. • Efforts to develop self-report methods of assessing the handicap
related to hearing loss have also been common and have occurred
over a number of years.
• Proposed instruments include the
• Hearing Handicap Scale,
• Hearing Measurement Scale,
• Social Hearing Handicap Index,’
• Denver Scale of Communication Function,’
• Hearing Performance Inventory

19. • These instruments all survey a number of communication areas.
• Stated purposes vary from an assessment of the effects of hearing
loss on an individual’s performance in everyday living activities
• To an assessment of communication attitudes.’
• Self-report inventories generally are utilized in aural rehabilitation
programs

20. • The relationships between audiometric formulas and self-report
measures of handicap are weak and appear unlikely to be assessing
the same issue.
• The decision on what constitutes a handicap depends to a
considerable extent on why the decision is being made.
• Clearly, definitions of handicap cannot be made separately from the
context of the need for the definition

21. Correlation
• Most (71.9%) of these participants had AHL but no SHD
(underestimated HI) while the rest (28.1%) had SHD but no AHL
(overestimated HI)
• Both non-auditory factors (demographic factors and medical
histories) and auditory factors (tinnitus and occupational noise
exposure)
• Were associated with discrepancy between self-reported hearing and
audiometry in multivariable analysis

22. • For demographic factors, participants who underestimated or
overestimated their HI
• Were significantly younger compared with participants who had
concordant HI
• It is well known that audiometric HL dramatically increases with
increasing age.
• SHD is also increased with age as difficulty of speech understanding in
adverse listening conditions increases due to decreased synaptic loss,
working memory capacity or impaired temporal processing

23. • For medical-related factors, participants who overestimated their HI
significantly had more hypertension and depression than those who
had concordant HI
• Because hypertension is known to increase the risk of cochlea
damage possibly through malfunction of the stria vascularis
• It might be related to early development of preclinical HL in auditory
way

24. • Also, hypertension and depression may influence the SHD in non-
auditory way.
• Subjects with hypertension have worse overall health than subjects
without hypertension,
• Which in turn has been shown to be associated with an increased
likelihood of reporting HD

25. • Studies have suggested that personality traits of neuroticism had a
more adverse perception of their HD,
• It is widely known as an important factor that influences depression.
• Accordingly, hypertension and depression may lead to an increased
perception of HD.
• Moreover, as the present study is cross-sectional, it cannot be
excluded that hypertension and depression is a result of SHD.

26. • For auditory factors, tinnitus and occupational noise exposure were
associated with concordant HI
• It is possible that these participants had an audiometric assessment
for their tinnitus
• Or occupational health screening programe and had known about
their hearing status.

27. • Participants who had been exposed to occupational noise tended to
have less underestimated HI regardless of tinnitus
• As they are more likely to have severe HL than other participants, the
severity of HL may affect SHD

28. • In summary, the prevalence of discrepancy between SHD and AHL
was 18.2%
• Age, medical histories of hypertension and depression, tinnitus and
occupational noise exposure
• Were associated with inconsistent results between self-reported and
audiometrically measured hearing assessment in multivariable
analysis.

29. • Understanding the factors related to self-reported hearing will assist
clinicians in interpreting subjective reports of hearing
• And using these data as a surrogate measure of audiometry.
• These factors need to be considered when determining whether to
conduct a hearing test, even if the patients do not report an HI

30. Determining Gain and Assessing Benefits
• In determining how a hearing aid will shape incoming sound to
accommodate a patient’s degree and configuration of hearing loss,
• a formula for gain is typically applied,
• which is a formula used to compute the desired amount of
amplification at each frequency.

31. • This strategy is referred to as a prescription procedure.
• For example, in one of the earliest prescription procedures, the goal
was to restore hearing thresholds to normal.
• The amount of gain prescribed at each frequency corresponded to
the degree of hearing loss.
• In a more recent prescriptive procedure, high frequencies are
amplified more than low frequencies to maximize speech audibility.

32. • Some prescriptive formulas determine targets for soft, moderate, and
loud sounds.
• Incorporated in most prescriptive formulas is the patient’s LDL, so
sound is not presented at an uncomfortably loud level.
• Most hearing aid manufacturers preprogram a hearing aid according
to their preferred prescription formula and the patient’s particular
hearing loss,
• But the audiologist can alter the settings using the manufacturer’s
computer software

33. Verification
• Implicit in the use of prescriptive methods of hearing aid selection is the
need to verify that the prescriptive targets have been met and that the
fitting is appropriate for the particular patient.
• Verification determines whether the hearing aid is acoustically working as
desired on the patient’s ear.
• Verification is typically accomplished with probe microphone technology
and is considered by the American Speech-Language-Hearing Association
(ASHA) and the American Academy of Audiology (AAA) as being the best
practice (AAA, 2006; ASHA, 1998).

34. • A small flexible tube is inserted into the ear canal and positioned near
the tympanic membrane.
• The tube connects to a microphone, which records the decibels of
power delivered at the end of the ear canal.
• First, sound is measured near the tympanic membrane, so the
measure is influenced by the natural resonance of the ear canal.

35. • Measurements are then repeated, but this time with the hearing aid
worn by the patient.
• These measures are called real-ear measures.
• Although these measures do not indicate how well an individual can
hear when wearing the hearing aid,
• Results indicate whether the hearing aid delivers the prescribed gain
at each frequency, also called the target gain.

36. • A recent trend has been to include speech mapping in the probe-
measure repertoire,
• Which ensures that the patient can optimally hear those frequencies
comprised by the speech spectrum.
• In this procedure, the patient wears the hearing aid while he or she is
coupled to the programming computer, along with a probe
microphone in the ear

37. • Continuous speech is presented at a constant level, typically twice,
once at a conversational level and then once at a fairly loud level.
• The output of the probe microphone displays on the computer
screen.
• This display is evaluated in terms of the patient’s audiogram, LDL,
targeted gain levels, and a spectral display of conversational speech.
• In particular, the soft and loud peaks of speech are assessed to ensure
that they do not approach an uncomfortable level but are loud
enough to be heard.

38. Validation
• In addition to verifying that a hearing aid meets particular targets,
validation measures are collected to ensure that hearing-related
disability has been reduced.
• Validation may entail collecting speech recognition measures and
subjective impressions.
• Speech recognition testing indicates the extent to which the patient
can recognize more speech with the hearing aid versus without the
hearing aid and ostensibly reflects a concomitant decrease in hearing-
related disability

39. • Patients are tested with and without their hearing aid, and the
amount of improvement in percent words correct is computed.
• According to Bentler (2009), the most commonly used tests for this
purpose are the CID W-22 Test (Hirsh et al., 1952), the NU-6 Test
(Tillman & Carhart, 1966), the Speech-in-Noise (SIN) Test (Killion &
Vilchur, 1993), the QuickSIN Test (Killion, Niquette, & Gudmundsen,
2004), and the Connected Speech Test (CST) (Cox, Alexander, &
Gilmore, 1987).

40. • The Hearing in Noise Test (HINT; Nilsson, Soli, & Sullivan, 1994) is also
recommended for this purpose (Mendel, 2011).
• A second, subjective procedure to validate hearing aid benefit is to
administer a questionnaire or an inventory.
• Patients may complete a checklist about what they can or cannot
hear with the hearing aid, and may indicate satisfaction with the
device

41. • Cox (2003) identified seven categories of self-report outcome data.
Choice of a particular self-assessment scale might be based on which
of these seven categories you are interested in assessing:
1. Benefit, or the change in hearing-related disability that has resulted
from the use of amplification
2. Satisfaction, or an overview of the physical, social, psychological, and
financial changes that have resulted from the use of amplification
3. Use time, which is often related to the severity of the hearing loss
and contextual factors, but is an indicant of how helpful and beneficial
the hearing aid is for the patient

42. • Residual activity limitations, or the hearing-related difficulties that the
patient continues to experience despite the use of amplification
• 5. Residual participation restrictions, or limitations that prevent an
individual from fulfilling a role in life
• 6. Impact on others, usually determined by a frequent communication
partner (not many instruments are available for this purpose)
• 7. Quality of life, including improvements in social life and mental
health

43. • Does my speech sound natural?
• Can you hear me clearly when I count from one to ten?
• Am I too loud?
• Does your own voice sound natural?
• Is it tinny or mechanical sounding?