Audiology Exam 3

-daily biologic calibration and listening check

-acoustic calibration (annual)

-exhaustive callibration (every two years)

1. prevents collapsed canals

2. hygiene (disposable)

3. greater sound separation between ears

4. greater attenuation of background noise

transfers energy from one format to another

-earphones/bone oscillators

forehead- more reliability

mastoir- allows more power to test at higher levels

-most use mastoid

turns vibrations into electrical signals

-oscillator

-attenuator

-interrupter switch

generates pure tones

controls the intensity level of the signal

controls the duration of the signal that is presented to the patient

-compressional

-osseotympanic

-inertial

primarily for high frequencies; skull vibrations sent directly to bony walls of cochlea

-skull vibrates segmentally

broad range of frequencies; skull vibrations sent directly to bony walls of ear canal and tympanic membrane

-skull vibration segmental and whole

primarily for low frequencies (100Hz and below); skull vibrates as a whole

-ossicles mimic the movement as a whole in the opposite direction

outwards as well as inwards

deflected backwards into the audiory system, causing more acoustic energy to reach the cochea

articifial enhancement of bone conduction hearing caused by occluding the ear (increased amount of sound reflected back to the cochlea)

-NOT an improvement in bone conduction hearing, only artificial

occlusion is at or near the concha; audiometric headphones we use cause this

low frequencies

250Hz = 15dB

500Hz = 15dB

1000Hz = 10dB

occlusion effect negligible above 1000Hz

less occlusion effect depending upon the depth of their insertion

-probably from lessening of the effects of osseotympanic bone conduction with further insertion

an occlusion effect; wax, foreign object, middle ear fluid, ossicular disarticulation, etc.

-usefull for asymmetric hearing loss

-select a 250Hz or 500Hz tuning fork, strike on bony prominence (not hard surface), place on patient forehead or midline of skull

normal: midline sensation of hearing, same in both ears (normal or equal loss)

abnormal: tone louder on one side; if conductive loss, louder on affected side, if sensorineural loss louder on contralateral side

greatest conductive component

the greatest conductive component or with the greatest sensorineural reserve

an occlusion effect

-causes more of vibratory signal to reach the inner ear

consistent and clear = credible

seat patients so they can't see your face but you can see theirs; 90-degree angle is good

-listen for tones, will be faint, one ear at a time, respond every time you hear a tone even if you just think you hear it; give instructions before placing ear phones on patient

-ask patient to remove hearing aids, glasses, etc. that might interfere with placement

-have patient pull hair back

-ask not to chew gum, smoke, drink, etc.

-phones off

better ear first- if neither better, either is fine

-AuD should do, not patient

-center ear phones directly over ear canal opening

-adjust headband to appropriate height

-if patient re-adjusts, check

-insert earphones places with outer flange at concha

-1-2 seconds "on"

-interval between tones at least 2 seconds

-familiarize patient with test tone at 1000Hz at audible level, if no response raise dB by 20

-start at 4-dB; if no response, raise by 20dB until first "yes"

-for each "yes", go down 10dB until first no

-at first no, go up by 5dB until "yes"

-repeat and stop when "yes" occurs 2/3 times at same level

-retest at 1000Hz- difference more than 5dB, reinstruct patient and start over

ANSI S3.21- standard

frequency in Hz (~250-8K)

hearing level in dB (starts from -10)

x = left unmasked

o = right unmasked

less than sign = left BC unmasked

greater than sign = right BD unmasked

square = left masked

triangle = right masked

] = left BC masked

[ = right BC masked

right ear = red ink

left ear = blue ink

no response, shown at limits of equiptment

headphones vibrate the head- some sounds reach normal ear so you need to mask

contralateralization of the signal; signal perceived by other ear

when stimuli presented to the test ear stimulates the cochlea of the non-test ear

supra-aural earphones: 40dB

insert earphones: 60dB

bone-conduction oscillator: 0dB

air conduction in good ear and bone conduction in test ear are the same because of interaural attenuation

pseudohypacusis

when the sound "covers up" another sound

done to eliminate one ear from the hearing test

ear getting masked and not being tested

just enough masking to shift the NTE

not enough masking, when the NTE is still participating in the test

you can STOP with accurate results for the test ear

too much masking, when the masker crosses over to the test ear

refers to the calibration of masking levels, tells exactly how much masking you're using

when both ears have large air-bone gaps and masking can only be introduced at a level that results in overmasking

-minimum is the same as initial

-two tones of the same exact frequency and phase are delivered to each other; right ear receives 80dB and left ear 40dB

-patient will report that a tone is heard only in the right ear (and vice versa)

-if tones the same, hear it in the middle of the head

-test unilateral pseudohypacusis

-if patient answers "yes" they're it's negative, if "no" they're faking

-can use to estimate threshold

-corroborate the PT audiogram

-word recognition

-differential diagnosis

-auditory processing

-estimating communicative function

1. speech-recognition threshold

2. speech-awareness threshold

3. word-recognition score

4. sensitized-speech measures

1000Hz

-monitored live voice

-use of recording materials

MLV- faster, just as accurate, more flexible (most clinics use)

recorded materials- more precise, accurate, reliable, normed

-measure of speech threshold

-typically use spondees

-75% right

-measure of clarity

-supra threshold

-typically use monosyllabic or sentence material

-recognize words enough to repeat

lowest level at which speech can be recognized or detected
>10 something's wrong

the lowest level in decibels at which spondees can be recognized correctly

-measure of threshold sensitivity for recognizing speech

-estimate of hearing sensitivity

bisyllabic word enunciated with equal stress on both syllables

lowest level in decibels at which speech can be recognized correctly

-sentences, spondees, etc.

lowest level at which listener can detect signal vs. actually understanding speech

50% of spondaic words can be identified

intelligibility curves rise from near chance to 100% performance within a few decibels; more accurate threshold

ability to correctly recognize speech at supra-threshold levels

-100% at 80dB HL

-96% at 40dB SL

useful in children and malingerers

uncomfortable loudness level - speech recognition threshold

-unchanged in conductive losses, can be much smaller in sensorineural hearing loss

client responds to words with set or open responses

phonemes appear with same frequency as in normal lexicon

levels above threshold (worse hearing), may indicate retrocochlear disorder

500, 1000, 2000 Hz (should agree with SRT)

-sign of presbycousis if not unless high-frequency losses

used for word-recognition testing (ex. "Say the word...") but not for SRT

present spondees, ascend by 10dB until patient responds, descend by 15dB; ascend by 5 until 2 correct

may be used when patient can't identify the words (ex. babies)

a decrease in speech recognition ability with increasing intensity level

process by which a constant audible tone becomes inaudible over time

four 50-word lists

-assess speech recognition for pediatric clients, 6 pictures to choose rom

word recognition scores obtained at a range of stimulus levels; may drop at higher levels (rollover)

8th nerve tumor

another speech word test; lists; distinguish initial and final target phonemes

giving directions and familiarizing patient with words is good, guessing okay