Test 2
interaural attenuation pure tone bone conduction
bone conduction: a signal presented through a bone conduction oscillator can cross from the test ear to the contest ear by vibration of the skull...the better cochlea will respond regardless of which ear is being tested -doesn't affect low frequencies and has a small loss of high frequencies, low vibrates skull where high vibrates segmentally
acuity
capability of cochlea
ear canal volume
children=.5-1cc adults=1.3cc smaller vol=possible blockage larger vol=2cc child or 2.5cc adult either tm perf or tubes
afferent connections
inner hair cells that go to the brain
0dB is
interaural attenuation for b/c
tympanometry
pressure measures in decapascal (daPa -normal: -50dp to 50dp -refer: -150dp -excessive negative pressure: type C, often seen in middle ear pathology, colds, etc -increasing stiffness: type B, seen with middle ear effusion, also with tm perf or tubes -increased compliance: type a, ossicular chain dis., history of tm ruptures -reduced compliance: otosclerosis, scarring
tympanometry tools
pressure pump (manometer), probe tone and microphone
shadow audiogram
should be ac=o and bc=40 but instead looks like its mimicking bc
spondee threshold
specifies the test stimuli used to obtain the speech threshold
central masking
a shift in threshold may occur for any masked event due to the presentation of noise, usually it will be no greater than 5dB
retrocochlear hearing loss pathology
absent or elevated acoustic reflexes despite good pure tone results use in PT who have functional hearing loss use to get estimation of hearing with children
cochlear hearing loss pathology
acoustic reflex is observed at a reduced SL (30-50dB SL) if hearing loss is too sever absent reflex
masking plateau
after you up threshold to 35 diff, if you do safety and they still hear it
if you can't obtain SRT then you try and obtain a
speech detection threshold, SRT is usually about 8-9dB greater than the SDT, PT doesn't have to identify word, only needs to recognize and respond to speech sound (let me know when you hear my voice)
if outer hair cells don't work,
then turn up volume because inner hair cells can still work and send info to the brain
make sound for SUT supra threshold because
we can hear this (SL above SRT), if if threshold 5, we do 45dB
masking problem
when art of masking needed exceeds the output of the audiometer
masking dilemma
when initial 15dB messes with test ear
interaural attenuation for pure tone air conduction
air conduction: a signal at high intensities can leak from under the headphones and put the skull into vibration -most studies have shown that this can occur at 45-50dB, the lowest level to cross is 40dB -use 40dB as IA level for air conduction
undermasking
whenever a masking noise is presented to the non test ear of insufficient intensity to stop the test signal from being audible in that ear
overmasking
whenever a masking noise is presented to the non test ear that is of sufficient intensity to shift the threshold in the test ear is beyond its true value
effective masking
whenever a masking noise is presented to the non test ear that is sufficient enough to stop the test signal from being audible
carrier phrase
-"say the word..." -not critical for SRT, just alerts PT -response may be repeating, writing, pointing to picture, etc
PAL PB 50
-50 monosyllabic words -the most commonly used monosyllabics -difficulty of each list was equivalent -phonetically balanced -always evolving because words most used changes -phonetic composition of each list same as the others (in regard to speech sounds, initial, medial, and final sounds) -phonetic composition of each list represented a normal sampling of speech sounds in english language
pediatric SRT
-ASHA recommends use of different spondee word list for children 6-12 -consists of words more familiar to the child -can also be used with ID PT's -with younger children, have them point to different body parts (show me your nose, show me your ear) (not true spondee test though) -unstandardized: if you don't have hearing test, cover mouth and ask to point to body parts with varying noise levels -always have hearing tested before SLP therapy
speech understanding word lists
-PAL PB-50
relationship between SRT and PTA
-SRT is compared with the 3 frequency PTA if these frequencies do not differ by more than 5db -SRT is compared to the best 2 frequency PTA when these thresholds at 2 of the speech frequencies differ by more than 10db -SRT and PTA are considered to be in agreement if they are within 8-10dB (if PTA at 10 and SRT at 0, you are okay)
use masking AC
-a masked air conduction threshold is needed for the test ear if the air conduction threshold for the test ear exceeds the true bone conduction threshold or ac threshold of the non test ear by 40dB or greater
use masking BC
-a masked bone conduction threshold for the test ear should be obtained whenever the air bone gap in test ear is 15dB or greater
masking for speech
-a masked speech recognition threshold is needed for SRT of the test ear if it exceeds any of the bc thresholds of the non test ear by 40dB (if exceeds bone conduction by 40 for 5,1,2) -need to mask for speech understanding ability when the presentation of the words exceeds 40dB of the bc thresholds in non test ear
PB max
-acuity for words -max score that the PT can obtain, to perform this test you need to present words at different )20-70) SL -most PB max scores are obtained at 40dB SL -percentage of words plotted as a function of intensity -phonetically balanced -usually 40dB SL, if drops turn up and if it gets worse after turning SL up, they may have tumor or distortion because softer sounds get through better than louder
acoustic reflex pathway
-arc is the contraction of the stapedius muscle of the middle ear in response to an acoustic activating signal -requires loud signal (70-100dBSL) to elicit bilateral reflex, stimulated either ipsilateral or contra laterally -2 ips arcs, 2 cont arcs
speech recognition thresholds
-compare relationship between speech and pure tone thresholds -gives reference intensity level for supra threshold speech tests (SL) -gives estimate of hearing sensitivity for speech range for difficult to test population -helps in assessment for amplification (hearing aids) -the lowest hearing level at which a person correctly recognizes the speech stimuli (spondee words) 50% of time
SRT procedure
-familiarize with test words, make sure they can say them -SRT is usually 4-5dB better (lower) if they are familiarized -present word at 40dBSL -if response is correct, decrease by 10dB -give one word per level until they miss a word, then go up 5dB and give 6 words until they get 3/6, then decrease by 10dB and give 6 words until they get 3/6 -lowest level they get 3/6 words is SRT -SRT validates PTA
SRT/PTA discrepancies
-functional hearing loss -instumentation malfunction -misunderstood instructions -pathology of central auditory nervous system including VIII nerve (processing problem) -age -cognitive disorder -language disorder
tympanometry
-measurement of the acoustic immittance of the ear as a function of the ear canal pressure -resulting graph (tympanogram) is an expression of how the immittance of the ear is altered when the canal is pressurized above and below normal -helps identify otitis media, otosclerosis, tm perf, occlusion, chain disarticulation
modes of presentation
-monitored live voice (can control rate of presentation, dialect may give advantage, can go at rate of PT, dialect may be disadvantage, not standardized) -calibrated tape recording (standardized, same voice, can't control rate, tape noise) -CD (standardized, won't wear out like tape, can't control rate of presentation)
speech understanding ability
-monosyllabic words, old test name was speech discrimination but ASHA changed it because it's an open ended test (using carrier phrase, not discriminatory) instead of a closed ended test (true discrimination, circle answer, pick answer out of pictures) -estimates degree of communicative function of PT -helps determine site of lesion -monitors progress of aural rehabilitation -helps assess hearing aid performance
other speech understanding tests
-northwestern university auditory tests NU4 and NU6 (most widely used (specifically) CVC tests) -based on perceptual phonetics/phonemics -particular speech sounds will vary depending upon sound that precedes/follows it -all NU words are CVC, 10 lists of 50 words -california consonant test -closed set response discrimination test with 100 CVC words -test consists of 4 words, stimulus word with 3 other words which differ in initial or final consonant (pat, mat, rat, bat) -test is sensitive for high frequency hearing loss
procedure for speech understanding tests
-present at 40dBSL -be careful of recruitment, you may need to decrease level if too loud for the PT -use phrase "say the word" -test each ear separately using 25 words
what type of masking
-pure tone masking=narrow bands of noise -speech masking=speech weighted noise -you can use broad band noise for either but it is not as efficient and needs more energy to be effective
PAL auditory test #9
-spondee words, first list that came about -familiarity with respect to vocabulary (5/6 grade level) -phonetic dissimilarity (airplane/hotdog) -normal sampling of english speech sounds (what sounds we usually use) -homogeneity with respect to audibility (words have same capability of being heard
acoustic reflex decay test
-test for retrocochlear pathology -stapedial muscle contraction should maintain for min of 10 sec -present the signal (either 5,1,2) either contra or ips at a SL of 10dB -watch for reduction or decay in the contraction of the stapedial muscle reflex of 50% of greater for 5 sec, if 50% or greater then it is retrocochlear pathology
word intelligibility by picture identification WIPI
-test used with children who cannot response or be understood verbally -child identifies and points to picture upon hearing stimulus word, there are several pictures that sound similar for them to discriminate against -used with children or adults with low cognition/stroke/TBI
PAL auditory test #9 improved
-two sets: W1 and W2 -words used most today -most commonly used test: CID W1/W2
masking for SRT
-use plateau method
CID W-22
-used most commonly for speech understanding -still 50 monosyllabic words -do not pause in "say the word bus" -can now use 25 words for each ear instead of 60 because it's testing normal speech (coarticulation) -4 lists -use a carrier phrase for natural context
occlusion effect BC
15dB @ 250hz 15dB @ 500hz 10dB @ 1000hz 0dB @ 2000hz and up
acoustic reflect pathway contralateral
1: primary auditory neuron (first order) goes to ipsilateral VCN 2: second order neuron goes from ipsilateral VCN to ipsilateral superior olivary complex (SOC) 3: third order neuron goes from ipsilateral SOC to contralateral facial VII nerve nuclei 4: forth order neurons go from contralateral VII nerve nuclei to contralateral stapedius muscle
acoustic pathway ipsilateral (same side)
1: primary auditory neuron (first order) of VIII nerve (hair cells of cochlea) to ventral cochlear nuclei (VCN) 2: second order neurons from VCN travel through the trapezoid body to ipsilateral facial nerve VII nuclei 3: third order neurons from ipsilateral VII nerve nuclei to ipsilateral stapedius muscle
purpose of acoustic reflex pathway
1: protect cochlea from loud damaging sounds 2: smoothing device for vowel speech sounds
for masking, only look at bone conduction to see if
40dB difference then start at AC and go
PAL PB 50 updated word lists and renamed it
CID W-22