First Year Exam Review

Classify the degrees of hearing loss

normal: 0-25 dB

slight: 15-25 dB for children only

mild: 26-40 dB

moderate: 41-55 dB

moderately-severe: 56-70 dB

severe: 71-90 dB

profound: 91+ dB

What are the different types of hearing loss?

CHL: abnormal air, normal bone, will have ABG

SNHL: abnormal air and abnormal bone, will have no ABG

Mixed: abnormal AC and BC, but with ABG present

What is distortional BC?

sound distorted by the vibration of the skull, primary mode

Skull vibrations compress skull bones, which puts pressure on the otic capsule and the membranous labyrinth, which compresses the scala vestibuli into the basilar membrane, which creates a traveling wave in the cochlea

What is inertial bone conduction?

secondary component due to ossicles

Skull bones vibrate due to inertia, and the ossicle will lag. Once ossicles are set into motion, they stimulate the cochlea

JUST LIKE AC HEARING!!!

What is osseotympanic bone conduction?

vibrations of the skull cause vibrations of the air in the ear canal allowing air molecules to strike the eardrum and stimulate the cochlea

What is fluid transmission?

Cerebral spinal fluid is being set into motion

What does bone conduction do?

measures cochlear sensitivity by bypassing the outer ear and middle ear by placing the oscillator on the mastoid to vibrate the skull and send sounds to the cochlea

Stiffness effects

low-frequency hearing (otosclerosis, negative middle ear pressure, fluid, tympanosclerosis)

-creates an upward-sloping hearing loss due to their being increased impedance in the lower frequencies

Mass effects

high-frequency hearing, such as fluid or TM thickening

What is the purpose of SRT?

to compare with the PTA and to validate thresholds

Is SRT a diagnostic test?

No, it is just a good cross-check for PTA

SRT should be _____ from PTA

6-10 dB

What is the procedure for SRT?

Present, go down by 10 dB until they miss a word, first word incorrect, stay at that level, and present three more words. If they get 50% correct, you are done testing. If they do not get 50%, go up by 5 dB and repeat

-Uses spondees

What is the purpose of WRS?

to assess the patient's ability to understand speech in quiet at a level loud enough to obtain a test score

What is MLV?

-not diagnostic

calibrate the voice using the VU meter. Need to speak with an even tone, conversational volume, faster than recorded, and inconsistent changes in score may be due to other variables

What is recorded?

Diagnostic tool

Calibrated with tone, slower than MLV, consistent, and changes in score are likely to be real

What is the most appropriate presentation level for the majority of hearing loss configurations?

UCL-5

What is UCL-5?

Confirms the loudest presentation level that is comfortable to ensure measuring a patient at their best performance

What is the procedure for UCL-5?

Raise your hand when my voice is uncomfortably loud

The clinician says the days of the week and will use loudness ratings to find the "uncomfortably loud level"

How to determine when masking is needed for speech

PL-IA and if audible to the NTE, you will need to mask

need to use broadband noise

What is the masking level equation for speech masking?

PL-IA + buffer

What are the normal ranges for tympanometry?

ear canal volume: 0.5-1.5 for adults, 0.3-1.0 peds

ME pressure (daPa): -150 to 50

SC: 0.3 to 1.7 cc

Gradient (TW): <200 daPa

What does tympanometry measure?

how the acoustic immittance of the middle ear system changes as air pressure is varied in the external ear canal and by measuring the SPL of probe tone in EAC

What does admittance mean?

total energy flow into a system

What does impedance mean?

total opposition to energy flow

What are the different types of tympanometry?

Type A

What is a Type A tymp?

normal middle ear function or normal eardrum movement

What is Type As?

shallow, consistent with excessive stiffness of the ME system, stiff ME, scarred or thickened TM or otosclerosis with CHL

What is type Ad?

values greater than 1.7 SC, tall

-suggest reduced stiffness, hypermobile TM, or ossicular discontinuity with CHL

What is type B?

no height, no width, or ME pressure, flat

-fluid in the middle ear or middle ear dysfunction

Fluid will have

normal ECV

Perforations or P.E. tubes will have

large ECV

Impacted cerumen may produce a

small ECV

What is type C?

abnormal middle ear pressure only, ETD

The probe tone frequency that is used for adults and children is

226 Hz

Why do we use a 1000 Hz tone for infants who are younger than 6 months?

They have a mass-dominated system, so their resonant frequencies will be lower

-have several mechanical changes to the outer and middle ear in the early months of life

-have an entire carilaginous EAC so it can collapse more easily

-have smaller ears in general

When using an 1000 Hz tone, you only look at the

peak to determine if it's normal or abnormal

True or false: you can switch from 1000 Hz to 226 Hz to confirm ECV

What are the stages of masking?

undermasking

effective masking

over masking

What is undermasking?

-Masker levels are less than the minimum masking, so both the tone and noise are both being heard by the NTE

-Masking is not loud enough

What is effective masking?

-range of masking levels between the minimum and maximum masking levels

-The test ear hears the tone, and the noise is heard by the NTE, allowing us to find the true threshold

What is the overmasking?

Masker levels are more than maximum masking

-Masking levels are so loud, they are crossing over to the test ear. This confuses the test ear and creates a masking dilemma

What is the masking dilemma?

minimum masking level exceeds maximum masking level

-typically seen with bilateral CHL

What is interaural attenuation?

Sound is attenuated (lost) as it crosses the head, reduction in intensity of sound (attenuation), and as it crosses the head from one ear to the other (interaural)

What is the concept of masking?

The perception of one sound being affected by the presence of another sound

-need to mask when sound is crossing over to the other ear

Why do we mask?

due to crossover to the non-test ear

How does crossover happen?

by bone conduction so sound travels to the non test ear cochlea

-WILL NEED TO LOOK AT BC OF NTE

What is the test ear?

the ear you want to find true threshold for

What is the non-test ear?

the ear you want to distract or do not want to participate in

What is the IA for inserts?

60 dB

What is the IA for headphones?

40 dB

What is the IA for bone conduction?

0 dB

How to calculate an individuals specific IA?

AC of test ear - BC of non-test ear

What is the minimum masking level for AC?

PL-IA + ABG NTE

What is the maximum masking level for AC?

BC+IA -5

What is the minimum masking level for BC?

PL+ABGNTE + OE

What is the maximum masking level for BC?

BC + IA -5

What is the minimum masking level for speech?

PL - IA + buffer (20-30 dB)

What is the maximum masking level for speech?

best bone + IA

What masker stimuli should you use for pure tones?

narrow-band noise

What masker stimuli should you use for speech?

broad-band noise (speech-shaped noise)

What are the occlusion effect levels for masking?

250: 20 dB

500: 15 dB

1000: 10 dB

What do we have to consider when masking BC?

the occlusion effect

What is the occlusion effect?

improvement of low-frequency BC thresholds when the ear is covered with inserts or headphones

-due to the ear canal being closed, sound reverberates in the ear canal, which will amplify sound and have a better threshold

Nedd to mask for BC when

The ABG is greater than 10 dB

What is the purpose of masking for BC?

to determine the type of hearing loss

Why do we perform the QuickSIN test?

to test speech understanding in background noise, and is more realistic to predict a patient's ability to understand speech in real-world environments

The QuickSIN is a

good counseling tool because it shows how well the patient is performing in real-world situations

How do we score QuickSIN?

25.5 - total correct = SNR loss

-need to do two lists and then average them

What are the different SNR losses?

normal: < or equal to 3

mild: 3-7

moderate: 7-15

severe to profound: >15

What is the speech intelligibility index (SII)?

to determine what % of speech is audible

Why do we use speech?

-Speech is more realistic than pure tones

-It can assess functional communication problems

-It assesses the distortion component of hearing loss, whereas pure tones only test audibility

What does SDT compare to?

compared to the best pure tone threshold

When do we use SDT?

When we cannot perform SRT, such as for very young children, speech/language delay, non-English natives, adults with severe to profound HL

How can you calculate the PI-PB function?

testing word recognition at multiple levels, which will show the patient's percent of recognition compared to the presentation level

What are the interpretation scores?

normal limits: 90-100%

slight difficulty: 89-75%

moderate difficulty: 74-60%

59-50%: poor discrimination

<50%: very poor discrimination

How to compare scores between ears or from one evaulation to another to determine if it is significant or not for WRS?

Carney and Schlauch table determines when a difference really is a difference included on the SPRINT chart

Judy Dubno data to determine when findings are “normal” included on the SPRINT chart

The PI-PB function can show

rollover for retrocochlear

0.45 = retrocochlear

If concerned for rollover, you can calculate by using

the rollover index (PBmax-PBmin divided by PB max)

True or false: want to reach PB Max to have 100% word understanding

true

The PI-PB function is the best to test at multiple levels to achieve

the psychometric function

When interpreting WRS scores, what information does it provide regarding the type of hearing loss

Psychometric functions with differing types of hearing loss

Conductive HL: will have excellent word recognition if it is presented loud enough

Cochlear or SNHL: range of WRS, issues with clarity will have a lower PB max?

Retrocochlear HL: when sounds get louder, their response got poorer indicating that there may be something more neural going on

What is the purpose of OAEs?

assess cochlear status (specifically OHCs), identify cochlear dysfunction before it is apparent with pure tone audiometry, monitor cochlear function

What are the intended populations of use for OAEs?

hearing screenings (newborns, peds, patients with disabilities), neural vs. sensory hearing loss, functional hearing loss, monitoring for noise exposure or damage, ototoxic monitoring, tinnitus, part of the hearing test barrery

What are the components of the DPgram?

noise floor: needs to be 6 dB above

stimulus level: needs to be between 55 and 65 dB SPL

-6 dB SPL absolute amplitude, needs to be between both criteria above

How to interpret DPOAE results?

Present when it is above -6 dB absolute amplitude and 6 dB above the noise floor, indicates healthy outer hair cell function consistent with normal hearing

Absent when it is below the noise floor, indicating that there is damage to the hair cells resulting in a hearing loss.

What are TEOAEs?

When would you not use QuickSIN?

If the patient has a profound hearing loss (PTA: > 80-90 dB)