behavioral audiological tests

includes: ABR, AIT

includes:

Tympanometry

Acoustic Reflex Testing

Evoked potentials (ABR, MLR, LLR, ASSR)

1. Part of standard test battery

2. includes tympanometry and ART

3. evaluates how well sound is transmitted

1. stiffness or springiness, mass, resistance

2. various pathologies can affect typical appearance of immittance measurements

1. identifies ME fluid

2. Eval. Vll and Vlll function

3. integrity of ossicles and TM

4. determines nature of HL and assists in diagnosis of site of lesion

5. predictive of audiometric findings

probe tip create hermetic seal

air pump and manometer

pure tone generator

=

measure how immittance changes as a function of applied air pressure

measured at +200daPa

children: above 2.0ml

adults: above 2.5ml

suggests TM perf

below .4ml clogged probe/occlusion

can derive middle ear volume:

adults: .3ml to 1.6ml

children: .3ml to 1.25ml

low or reduced SM: OM, otosclerosis, cholesteatoma

high or elevated SM: ossicular discontinuity

1. impedance down admittance up (opp +200)

2. adults low as -50dPa normal

3. children low as -125dPa is normal

below norm: eustachian tube dysfunction (ETD) or OM

1. stapedeous or acoustic reflex occurs in both ears when a high intensity sound is presented to at least one ear

2. neural transmission reaches superior olivery complex

3. stiffens ossicular chain

4. impedance increase admittance decrease

bilateral response:

1. ipsilateral: 500, 1000Hz

2. contralateral: 500, 1000, 2000Hz

3. usually occur btwn 85 & 100dBSL for auditory threshold always tested at TPP

4. lowest dbHL level that produces a change in admittance (.02ml)

1. a low intensity sound generated by the outer hair cells of the inner ear (function) need to have normal mid ear function

2. greater understanding of cochlea function: has active processes (cochlear amplifier), OAE generated by healthy cochlea, OHC movement

1. no more than middle to moderate HL

2. normal mid ear function

3. clear outer ear

4. unaffected by sleep

5. patient still and quiet

1. excellent screening tool for all ages

2. useful cross check for basic audiological evaluation

3. can differentially diagnose sensory vs neural HL

4. cannot determine degree of HL or amount of cochlear damage

1. spontaneous otoacoustic emission (SOAE)

2. clinical useful OAEs:

transient evoked: broad band clicks elicit response

distortion product: two pure tones elicit another tone the cochlea generates

1. quick reliable accepted by those who receive it

2. high sensitivity and high specificity

3. goal is to identify those individuals who have hearing impairment

4 outcomes of OAE screening:

Two Correct

sensitivity: proportion of abnormals who fail = HIT RATE (have HL)

specificity: proportion of normals who pass (no HL)

4 Outcomes of screening:

Two Incorrect

False negative: abnormal passes test (have HL but pass the test)

False positive: normal person fails (no HL but fail which means they do have HL when they don't)

1. 1 in 1000 born with HL over 50dBHL

2. 2.5 in 1000 born with HL of 20 dBHL

3. want to catch HL right away early intervention is key

1. universal access newborn hearing screening within 1 month

2. confirmation findings prior age 3 months

3. after indication intervention start prior to 6 months

4. pass screening risk factors followed prior to kindergarten

5. families rights informed consent

6. confidentiality

7. info systems report to Dept of Health

8. quality assurance: setting bench marks

1. family hist hereditary childhood sensneur HL

2. inutero infection STORCH

3. craniofacial anomalies

4. birth weight less 3.3 lbs

5. hyperbilirubinemia require exchange transfusion

6. ototoxic meds

7. apgar score 0-4 1 min, 0-6 5 min

8. mechanical ventilation 5+ days

9. stigmata

1. concern regard hear, speech, dev delay

2. bacterial meningitis other infection HL

3. head trauma

4. stigmata

5. ototoxic meds

6. recurrent OM effusion for at least 3 months

1. neurodegenerative disorder

2. anatomic deformities/disorders affect eustachian tube

3. recurrent OM effusion

evaluation to find anatomical location of an abnormality (cochlea vs. retrocochlea)

evaluates the patients perception of intensity& how it's affected by the pathology

tests tone adaptation due to reduction of neural response

1. present a tone 2000 Hz at 20 dBSPL

2. patient raise hand whole time hear tone usually 1 min

3. patient not hear for 1 min test positive for tone decay (not enough neurons firing

presence of loudness recruitment may indicate cochlea HL

1. present tone to control ear patient match tone

2. look at whether loudness grew louder on test side rather than the control side

Two types:

a. ABLB:alternate bineural loudness balance

b. monoloudness balance

smallest intensity difference that can be detected

1. short increment sensitivity index (SISI)

a. patient really good at naming 1 dB increase they would have loudness recruitment bc in general no one should be able to hear 1 dB intensity difference

measures summating potentials from hair cells and action potentials from auditory nerve

1. help define 1st peak ABR

2. used to monitor cochlea and auditory nerve (Meniere's Disease)