Audiology 101 SOFT HIGH PITCH LOUD. How do we hear? Ear to the Brain. Main parts of the Ear

Transcription

1 Audiology 1 How do we hear? Main parts of the Ear Hear We Go! 6 Lori A. Van Riper, MS CCC-A University of Michigan Health System Sound Support Outer -pinna, ear canal eardrum Middle -air filled, ossicles Inner -fluid filled cochlea, hair cells Ear to the Brain j zv mdb n ng e l u i o a r p h g ch sh k f th s LOW PITCH HIGH PITCH 1 1 SOFT LOUD 1

2 AUDIOGRAM OF FAMILIAR SOUNDS AUDIOGRAM OF FAMILIAR SOUNDS Normal Hearing Speech Banana Mild Loss Moderate-moderately severe Loss Severe Loss Profound Loss Degrees of Hearing Loss 1 1 j z v mdb n ng e l u i o a r p hg ch sh k f th s Testing Hearing in Children Air Conduction (A/C) Bone Conduction (B/C) Reading symbols on an audiogram O = Right Ear air conduction X = Left Ear air conduction ^ < > [ ] = Bone conduction S = Soundfield (speakers-no earphones) 2

3 Four Types of Hearing Loss 1. Conductive 2. Sensorineural 3. Mixed 4. Auditory Neuropathy/Dys Dys-synchronysynchrony Conductive Hearing Loss Occurs in outer and/or middle ear. Sound is blocked from getting to inner ear May be caused by: Fluid or infection in the middle ear Deformity in ear structures Atresia (no ear canal) Blockage in ear canal (wax, bead, etc.) Eardrum perforation Example of conductive hearing loss < j O z v mdb n ng e l u < O i o a r < O p hg ch sh < < O k O f th s Sensorineural hearing loss Problem in the inner ear (cochlea) or along neural pathway that carries sound to the brain Hair cells not functioning Approximately % are from birth Prenatal infections, genetic, syndromic Approximately % are acquired Meningitis, genetic, ototoxic, neonatal risks Example of Sensorineural hearing loss j < O z v mdb n ng e l u i o a r < O < O p h g ch sh <O k < O f th s <O Mixed hearing loss Combination of conductive and sensorineural hearing loss Involves both the outer/middle ear and the inner ear. Causes from birth Middle and inner ear deformity, syndromes Acquired causes Head injuries, middle ear diseases, syndromes 3

4 Example of mixed hearing loss p z v h > g ch j mdb sh n > i ng o a r e l u > X X X > > X X k f th s X Auditory Neuropathy or Auditory Dys-synchrony synchrony Inner ear and/or hearing nerve problem Auditory problem and neuro problem Sometimes associated with medical complications in neonatal period. Behavioral responses in these children range from normal to looking profoundly deaf. At risk for poor speech-language development or progressive auditory problems Incidence of hearing loss in infants In the normal newborn population, the incidence of hearing loss is Prevalence of hearing loss 1/ 1/, 5/, 2/ Incidence of hearing loss in infants In the normal newborn population what is the incidence of hearing loss? 1/ 1/, 5/, 2/ Incidence of hearing loss in infants In the medically high-risk population, 6-/ will have some type of educationally significant hearing loss 4

5 Red flags for hearing loss Family history of hearing loss Lack of responsiveness to sounds/voices Limited babbling/vocal play Cannot be calmed by sound alone Delayed speech/language development Language development w/poor articulation Developmental delays Parent or caregiver concern Is the hearing loss permanent? Temporary hearing loss Most conductive, rarely sensorineural (mostly ear infections and middle ear fluid, sometimes viral infection can cause sensorineural loss that improves in time) Fluctuating/Progressive hearing loss Some sensorineural, some mixed, some conductive (certain causes associated w/fluctuant hearing) Permanent hearing loss Permanent hearing loss Mostly sensorineural; cannot be medically fixed Some actually worsen over time. Infants/children with permanent hearing loss need intervention immediately; language intervention and/or hearing aids/cochlear implants EHDI Programs Screening: : in Michigan, >94% newborns are screened at birth for hearing loss Referral in one or both ears means they require a re-screening If re-screening not normal, diagnostic testing is completed to determine if there is hearing loss Early-On Screening AuDX Screening tool-referral means to refer to audiologist or pediatrician Earcheck monitor Screening tool-doesn t test hearing but checks for middle ear fluid Not to be used less than 6 mos. of age Referral on either of these means there may be a problem and they need to move on to the next level Early-On Screening AuDX best option for hearing screening Pass/refer only, no interpretation Does it tell you the type or degree of hearing loss? Re-screen by AuDX in 1 month Refers again,, make referral for diagnostic testing 5

6 Otologic/Audiologic Test Results If a child is 18 months or younger, then hearing tests used to determine eligibility must have been done within last 3 months If a child is over 18 months, hearing tests must have been done within last 6 months Otologic medical evaluation always within last 6 months Diagnostic Audiologic Tests Electrophysiologic (Objective) ABR-Auditory Auditory Brainstem Response any age OAE-Otoacoustic Otoacoustic Emissions any age Tympanometry and acoustic reflexes any age Behavioral (Subjective) BOA-Behavioral Behavioral Observation Audiometry -66 mos. VRA-Visual Visual Reinforcement Audiometry 6 mos-2 2 yrs. Conditioned Play Audiometry years Auditory Brainstem Response Also known as ABR ABR,, BAER, AEP, BAEP Measures brain activity in response to sound Gives estimate of hearing in each ear Baby must sleep! birth to 4 months in natural sleep; older children will need to be sedated ABR-What should parents expect? Skin is gently cleaned of oils on forehead and behind ears Sticky electrodes placed on forehead and behind each ear. Soft earphones placed in ears Baby sleeps while test is completed Testing is hours Otoacoustic Emissions Also known as OAE s, DPAOE s, TEOAE s Cochlea echos echos sound back through middle ear and these vibrations can be measured Does not tell degree of hearing loss OAEs present,, may still be mild loss or auditory neuropathy/dys dys-synchronysynchrony OAEs absent,, may mean many things: middle ear fluid,hearing loss,??? OAE-What should parents expect? Small, soft probe is placed in each ear Computer makes soft clicking sounds in the probe Baby needs to be quiet but not necessarily asleep Testing takes seconds to a couple of minutes per ear Separate ear information can be obtained in a few minutes 6

7 Tympanometry Tympanometry (Immittance) measures compliance of eardrum and middle ear bones Identifies fluid, hole in eardrum, etc. Does not measure hearing Can be done at any age Tympanometry-What should parents expect? Small soft probe placed in ear canal Air pressure is changed in the ear while soft tone is played in the ear Takes 5 seconds if child is quiet Longer on screaming child Behavioral Observation Audiometry (BOA)( Infants - 6 months or developmentally delayed children at this cognitive level Tester behind child and caregiver, presents Hear-kit noisemakers at ear level on each side out of the peripheral vision of the child. Examiner s voice played through speakers in soundbooth (speech detection threshold) Behavioral Observation Audiometry (BOA)( Responses from infant -33 months; awakens, eyes widen, body parts move, start or stop sucking, eye blink, eye-brow lift 4-66 months; begins searching for sound, lateralizes, smiles to some sounds (usually voices), reaches out for noisemakers Behavioral Observation Audiometry Visual Reinforcement Audiometry (VRA( VRA) 6 mos.-2 2 ½ years Child is on caregiver lap Child is taught to turn to look for sound or voice and is rewarded by seeing animal light up Can get hearing threshold information in the soundfield (better ear information) with insert earphones (separate ear information) 7

8 Visual Reinforcement Audiometry Play Audiometry 2 ½ - 3 years and older Teach child to drop a block, place a peg, throw a ball, etc. when he/she hears a tone Can obtain specific information at child s hearing threshold Also obtain speech reception threshold by having child point to body parts, point to selected pictures or repeat words 6 months-2 2 1/2 years Play Audiometry 2 ½ years and older 9 month old JJ passed her newborn hearing screening Caregivers are concerned about hearing She doesn t recognize her name She appears to have developmental delays behaviorally but not physically She has had 6 ear infections since birth She refers on the AuDX She refers on the EarCheck What s the next step? 9 month old JJ passed her newborn hearing screening Caregivers are concerned about hearing She doesn t recognize her name She appears to have developmental delays behaviorally but not physically She has had 6 ear infections since birth She refers on the AuDX She refers on the EarCheck Refer for diagnostic testing to rule out hearing loss 18 month old Ci has cerebral palsy Parents do not suspect hearing loss She produces no words, but understands mama, dada, bottle and Juno (dog) She has had only one ear infection She refers on the AuDX Next step? 8

9 18 month old Ci has cerebral palsy Passed her newborn hearing screening Parents do not suspect hearing loss She produces no words, but understands mama, dada, bottle and Juno (dog) She has had only one ear infection She refers on the AuDX She should be referred for audiologic evaluation 3 month old baby R Referred by audiologist with diagnosis of auditory neuropathy No ear infections Passes AuDX screening Parents report baby responds to sounds at home Next step? 3 month old baby R Referred by audiologist with diagnosis of auditory neuropathy No ear infections Passes AuDX screening Parents report baby responds to sounds at home Eligible for services because 2 year old AJ has delayed speech and language Parents do not suspect hearing loss He passed his newborn hearing screening He was premature and on a ventilator at birth He has audiologic evaluations every 6 months for monitoring. He passes AuDX screening Does he need diagnostic referral? 2 year old AJ has delayed speech and language Parents do not suspect hearing loss He passed his newborn hearing screening He was premature/on a ventilator at birth He passes the EarCheck and the AuDX He has audiologic evaluations every 6 months for monitoring. Diagnostic referral? No request test results from audiologist to confirm parent report of normal hearing 9

10 7 month old tested by VRA following bacterial meningitis Tympanograms are normal OAEs are absent Baby AAA Baby BBB ABR report on 3 month old says: 45 db sensorineural hearing loss bilaterally Tympanograms normal Absent OAEs Girl CCC 2 ½ year old with delay in speech & language Many ear infections in the past Age months Delayed speech & language Has had 3 sets of PE tubes in ears Some autistic-like behaviors Boy DDD Boy EEE 2 years, 9 mo. old Referred on preschool hearing screening Speech-language development is good Baby FFF 4 month old has ABR results of: 45 db conductive hearing loss bilaterally OAE s absent in each ear Tympanograms flat in each ear Scheduled for placement of PE tubes soon

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