Figure 13.1: Structure of the Ear. Outer ear Middle ear Inner ear Auditory nerve
Sound waves are first collected in our outer ear (called the auricle or pinna), pass through our ear canal and cause our eardrum to vibrate. These vibrations are in turn transmitted to our inner ear by the bones of our middle ear. Our inner ear plays a vital role in the transformation of these mechanical vibrations into electrical impulses, or signals, which can be recognized and decoded by our brain. When the vibrations reach the cochlea through movement of the bones in the middle ear, the fluid within it begins to move, resulting in back and forth motion of tiny hairs (sensory receptors) lining the cochlea. This motion results in the hair cells sending a signal along the auditory nerve to the brain. Our brain receives these impulses in its hearing centers and interprets them as a type of sound.
90 decibel loss Hard of hearing also called partial hearing
Not all children with hearing loss receive special education services. If communication methods are effective, there may not be an educational disability. MOST children with hearing loss do experience educational disabilities b/c of the communication differences and how the hearing loss manifests itself in typical classroom settings
Conductive Hearing Loss Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones, or ossicles, of the middle ear . Conductive hearing loss usually involves a reduction in sound level, or the ability to hear faint sounds. This type of hearing loss can often be medically or surgically corrected. Examples of conditions that may cause a conductive hearing loss include: Conditions associated with middle ear pathology such as fluid in the middle ear from colds, allergies (serous otitis media), poor eustachian tube function, ear infection (otitis media), perforated eardrum, benign tumors Impacted earwax (cerumen) Infection in the ear canal (external otitis) Presence of a foreign body Absence or malformation of the outer ear, ear canal, or middle ear Sensorineural Hearing Loss Sensorineural hearing loss occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear (retrocochlear) to the brain. Sensorineural hearing loss cannot be medically or surgically corrected (although there is treatment in form of cochlear implant). It is a permanent loss. Sensorineural hearing loss not only involves a reduction in sound level, or ability to hear faint sounds, but also affects speech understanding, or ability to hear clearly. Sensorineural hearing loss can be caused by diseases, birth injury, drugs that are toxic to the auditory system, and genetic syndromes. Sensorineural hearing loss may also occur as a result of noise exposure, viruses, head trauma, aging, and tumors. Mixed Hearing Loss Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. In other words, there may be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss. Any of these types of loss can occur unilaterally – in just one earConductive Damage to inner or outer ear Can be temporary Sensorineural Inner ear damage Tiny hair cells do not function normally Cochlea does not work correctly Message not transmitted to brain via auditory nerve Mixed central deafness: much more rare. Lower auditory pathways function normally, but the brain does not process the signal as sound. Caused by problem in central nervous system.
Hearing loss gets worse over time Estimated 28 million people have hearing loss Approximately 11million have significant irreversible hearing loss 1 million are deaf Only 5% are under 17 years of age 43% are over 65 years of age Higher education and income level correlates with lower risk of hearing loss (prenatal care, types of jobs, exposure to noise, early medical treatment for illnesses like ear infections)
Distinction between congenital and acquired is crucial – did they learn any language before the loss? Congenital Factors Heredity Conexin 26, genetic disorder if both parents have flawed copies of beta 2 gene Otosclerosis – stapes unable to function Prenatal disease Rubella – mostly sensorineural CMV – most common virus in newborns ATRESIA – conductive loss. External canal malformed or absent. Blockage of ear canal so sound can’t be transmitted to inner ear Acquired factors Postnatal disease Measles, mumps, influenza, scarlet fever Meningitis Otitis media – ear infections! Highly correlated with hearing problems, enough to impact language development in some cases Environmental factors Exposure to very loud noise for prolonged periods of time – explosions, loud engines, sirens, concerts)
Prelingual loss vs .postlingual loss PRE lingual;: congenital hearing loss, precedes the onset of speech or learning spoken language; it is severe, stable, and less common than postlingual hearing loss Post-lingual loss: People with this type of deafness became deaf after some exposure to the human voice. It will be easier for these people to acquire speech because the brain has some awareness of the rhythm and patterns of spoken language.
INTELLIGENCE: Similar to hearing peers, but a function of language development Deficits are related more to speaking, reading, and writing English rather than actual intelligence Processes information slowly, which may appear as cognitive impairment, but its not SPEECH/LANGUAGE: Depends on amount of residual hearing and age of onset Speech develops at much slower pace Can’t hear unvoiced sounds (/s/, /sh/, coughs) Congenital defaness, almost immeditate effect on development – less babbling EDUCATIONAL: significantly delayed School is based on spoken and written english Reading performance is most effected. Special interventions must be taken to teach reading Reading several years behind peers SOCIAL: Any time someone is unable to receive all of the information in a situation, their ability to participate is affected Missing sounds, reduced loudness, distorted sounds Changes perceptions of social interactions Delayed language or different language (ASL) can lead to limited social opportunities DEAF CULTURE is a culture where deaf people do not feel isolated, but bonded together in their similar language, traditions, and heritage. Identify as being of a unique culture, not disability Deaf vs/ deaf
The sounds we use to produce speech in conversation have frequencies and decibels. The most typical frequency and decibel for each speech sound has been graphed on an audiogram to provide information about what sounds can be heard at specific degrees of hearing loss. A child that can hear the sounds of speech will have a much easier time imitating, understanding and learning spoken language. When all the sounds necessary for speech were initially graphed and a line was drawn around them, the shape looked like a banana. The term &quot;speech banana&quot; was coined. This area is the target hearing area for children with hearing loss. If they are able to hear sounds within the speech banana when they are aided with hearing aids, there is a better chance they will understand that sound and be able to reproduce it in their speech.
4 main approaches to teaching communication skills, controversy about which is “best” Must take needs of individual into consideration when choosing which method or combo of methods to use This is VERY brief and does not include more specialized methods ASL – American Sign Language 6000 signs Represent concepts rather than individual words Sign systems – visual equivalent of the oral language through manual gestures (fingerspelling, signed english) Bicultural-bilingual: promotes ASL as primary language and English as a second language. Teach academic content in primary language,” DEAF children are not disabled, they are bilingual” Cued speech – hand signals near mouth that provides information about sounds that you can’t obtain by speechreading alone Total comm philosophy: simultaneous presentation of sings AND speech will give the maximum opportunity to understand and use both systems
Type of aid depends on age and type of loss and any other physical conditions that might exist. Hearing aids amplify sound – don’t always make sounds clearer In the ear aids contain all components (microphone, amplifier, transducer, and battery), generally for mild losses and not for little children Cochlear implants only for people who would not benefit from a hearing aid – click for youtube animation
Alldeaf.com: message board Baby getting CI turned on: http://www.youtube.com/watch?v=HTzTt1VnHRM My son is deaf: http://www.youtube.com/watch?v=-YN5Fdz1En0
Vision is the act of seeing with the eye Anatomy page 348 COMPLEX: link to the physical world GAIN INFO BEYOND SENSES: helps us integrate information that we acquire through the other senses (touch tells us what we are feeling (furry, soft) but our eyes confirm that it’s a puppy. We smell something sweet baking, but we must see it with our eyes to know it’s cookies PERCEIVE STIMULI: just like hearing loss, age of onset is important because it determines how the individual processes stimuli, if they have a visual memory or not
Legal blindness: 20/200 or worse in better eye, after correction Page 349 for field of vision pics Visual field 20 degrees or less What matters is how we instruct – are they using vision for learning or not?
About 10,800 deaf-blind children in US (older stat though)
ROP from receiving too much oxygen as a low birthweight preemie, peaked from 1940-1960, but still occurs today in some cases) scar tissue behind the eye 80% of preschool aged blind children had ROP
INTELLIGENCE Age of onset also critical – loss prior to age 5 affects visual memory Mainly affected by limited learning experiences Impairments in spatial concepts SPEECH/LANGUAGE: Develop at slower rate, but generally can acquire fluent speech and language Not able to visually associate spoken words with objects ACADEMICS: at least 2 years behind peers Again, limited learning opportunities , less prior knowledge Absence from school, delayed start to school Reading skills – decoding and comprehension – are delayed due to time it takes using braille or large print SOCIAL: Usually socially isolated, don’t usually initiate with other people Don’t see nonverbal cues/body language, so they don’t pick up on it – impacts their social interactions Exclusion from typical social experiences decreases the chance they will learn any social skills ORIENTATION/MOBILITY: Unable to orient to objects/people b/c they can’t see them Unaware of where they are in space May restrict their own movements b/c of fear of hurting themselves Likewise, caregivers may overprotect rather than teach effective mobility training PERCEPTUAL MOTOR: Usually have limited perceptual skills – texture, weight, sound discrimination Not necessarily true that vision impairment gives rise to enhancements in other sensory areas – no real data to support that
http://news.bbc.co.uk/local/tyne/hi/people_and_places/newsid_8758000/8758814.stm Video link in “ellas story” title
Assessment should focus on visual capacity, attention, and processing. All of these things will tell us how the individual uses their remaining vision, which will inform our interventions Mobility: must be an important focus in educational program. Safety and independence in the world is of utmost importance. lack of mobility is the most restrictive outcome of vision loss. long canes, sensors, laser canes, sonicguides (ultrasound waves against objects into sound) Daily living skills also critical for independence as an adult Instruction: Focus on receptive and expressive language skills to enhance understanding of auditory world Abstract math concepts difficult due to lack of spatial perception and intangibility Open and closed programs exist – most go to public school Mary Mike and Josh Communication media: next slide
Hearing and Vision Loss
Chapter Thirteen SENSORY IMPAIRMENTS: Hearing and Vision Loss
AUDITION <ul><li>The act or sense of hearing </li></ul><ul><li>The ear is the mechanism through which sound is collected, processed, and transmitted to a specific area in the brain that decodes the sensations into meaningful language. </li></ul>
Animation of normal hearing <ul><li>wikispace </li></ul>
DEFINITIONS/TYPES OF HEARING LOSS <ul><li>Deaf </li></ul><ul><li>Hard-of-hearing </li></ul><ul><li>Age of onset </li></ul><ul><ul><li>Prelingual </li></ul></ul><ul><ul><li>Postlingual </li></ul></ul><ul><li>Anatomical site of loss </li></ul><ul><ul><li>Conductive loss </li></ul></ul><ul><ul><li>Sensorineural loss </li></ul></ul><ul><ul><li>Mixed hearing loss </li></ul></ul>
DEFINITIONS OF HEARING LOSS DEAF HARD OF HEARING Hearing loss > 90dB Hearing loss 16-90dB Vision is primary input Some degree of residual hearing Cannot understand speech through ear Use of residual hearing and/or hearing aid to process speech
IDEA defines deafness as… <ul><li>“ a hearing impairment which is so severe that the child is impaired in processing linguistic information through hearing , with or without amplification, which adversely affects educational performance .” </li></ul>
TREATMENT FOR HEARING LOSS <ul><ul><li>Hearing Aids (Amplification) </li></ul></ul><ul><li>Surgical Intervention </li></ul><ul><li>Functional restructuring of external deformations </li></ul><ul><li>Atresia </li></ul><ul><li>Prosthetic stapes capable of vibration </li></ul><ul><li>Reconstruction of eardrum </li></ul><ul><li>Cochlear implants </li></ul>
Deaf Culture <ul><li>www.alldeaf.com </li></ul><ul><li>Sound and Fury documentary site </li></ul><ul><li>www.deaf-culture-online.com </li></ul><ul><li>Baby getting CI activated for 1 st time </li></ul><ul><li>“My son is deaf” </li></ul>
Professionals <ul><li>Otologist </li></ul><ul><ul><li>Medical specialist that studies the ear and its diseases </li></ul></ul><ul><ul><li>Extensive screenings for hearing problems </li></ul></ul><ul><ul><li>Purely medical/biological focus </li></ul></ul><ul><li>Audiologist </li></ul><ul><ul><li>Determines nature and severity of loss </li></ul></ul><ul><ul><li>Focuses on functional impact for the individual </li></ul></ul><ul><ul><li>Works with otologist to fit with right amplification system for the person </li></ul></ul>
Instructional Tips for Deaf or HoH Students <ul><li>Model how to write in complete sentences </li></ul><ul><li>Visibility of the rest of the class </li></ul><ul><li>Gaps in learning are common </li></ul><ul><li>Relay announcements/messages they may miss </li></ul><ul><li>Scripts for videos in class </li></ul><ul><li>Encourage peer support or peer buddies </li></ul><ul><li>Keep in close contact with audiologists and SLP’s </li></ul>
VISUAL PROCESS <ul><li>Very complex </li></ul><ul><li>Helps us gain information beyond the other senses </li></ul><ul><li>The way we perceive visual stimuli provides foundation for the development of more complex learning structures. </li></ul>
DEFINITIONS OF VISION LOSS <ul><li>BLIND </li></ul><ul><li>Legal blindness </li></ul><ul><li>Vision can’t be corrected to better than 20/200 in the better eye after correction </li></ul><ul><li>Some residual sight is common </li></ul><ul><li>Acuity and field of vision affected </li></ul><ul><li>Unable to use vision as primary avenue for learning </li></ul><ul><li>PARTIAL SIGHT (LOW VISION) </li></ul><ul><li>Acuity greater than 20/200 but not greater than 20/70 in better eye </li></ul><ul><li>Vision is primary source of learning </li></ul>
PREVALENCE <ul><li>Difficult to determine </li></ul><ul><li>20% of Americans have some kind of vision loss; most can be corrected </li></ul><ul><li>3% of total population will require specialized services </li></ul><ul><li>1 in 3,000 children are legally blind </li></ul>
CAUSES GENETIC ACQUIRED Albinism Prenatal exposure to radiation/drugs Retinitis pigmentosa Fetal infection (rubella, syphilis) Retinoblastoma Infections: nfluenza, mumps, measles Optic atrophy Vitamin A deficiency (extreme) Cataracts Retinopathy of prematurity Severe myopia from retinal detachment Trauma to eye Corneal lesions Tumors Iris abnormalities (coloboma or aniridia) TBI – cortical visual impairment Microphthalmia Macular degeneration Anophthalmia glaucoma
CHARACTERISTICS <ul><li>Intelligence </li></ul><ul><ul><li>Loss prior to 5 years old affects visual memory </li></ul></ul><ul><li>Speech and language skills </li></ul><ul><ul><li>Slower rate, limited ability to visually associate spoken words with objects </li></ul></ul><ul><li>Academic achievement </li></ul><ul><ul><li>At least 2 years behind peers, generally </li></ul></ul><ul><ul><li>Less prior knowledge, low reading skills, limited learning opportunities </li></ul></ul><ul><li>Social development </li></ul><ul><ul><li>Can be socially isolated and excluded from typical social experiences </li></ul></ul><ul><li>Orientation and mobility </li></ul><ul><ul><li>Unaware of location in space, may restrict movement for fear of getting hurt, need for mobility training </li></ul></ul><ul><li>Perceptual-motor development </li></ul><ul><ul><li>Usually limited perceptual skills (texture, weight, sound discrimination) </li></ul></ul>
Ella’s Story <ul><li>WAGR Syndrome </li></ul><ul><ul><li>Babies born with WAGR syndrome often have Aniridia, where the iris is missing, and have a 50/50 chance of developing Wilms’ Tumor, a form of kidney cancer in children. They can also be prone to genito-urinary problems and intellectual disabilities. </li></ul></ul><ul><ul><li>Degenerative vision loss </li></ul></ul><ul><ul><li>Tumors, chemotherapy </li></ul></ul><ul><ul><li>Developmental delays due to medical interventions and limited sensory input </li></ul></ul><ul><ul><li>http://www.cureaniridia.co.uk/ </li></ul></ul><ul><li>Ella </li></ul>
EDUCATIONAL SUPPORTS AND SERVICES <ul><li>Assessment </li></ul><ul><li>Mobility Training </li></ul><ul><ul><li>Daily Living Skills </li></ul></ul><ul><li>Instruction </li></ul><ul><ul><li>Mary, Mike, and Josh </li></ul></ul><ul><li>Communication media </li></ul>