Term
| Sounds that originate in the cochlea and propagate through the middle and outer ear. Measurable using sensitive microphones placed in the ear canal |
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Definition
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Term
-In the mid 1800s, German physicist Hermann von ___
observes that air-filled cavities are tuned to specific resonant frequencies
-von Helmholtz believed that the auditory system was composed of these resonators (“harmonic oscillators”), which responded to the movement of the ___ ___
-While not physiologically accurate, von Helmholtz was
fundamentally correct that the cochlea acts as a ___ ___ |
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Definition
Helmholtz; basilar membrane; frequency
analyzer |
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Term
-In 1928, Georg von Békésy describes the ___ ___ in the cochlea
-von Békésy disagreed with von Helmholtz: he did not believe it
was possible for there to be cochlear resonators tuned ___ enough to account for high-frequency hearing loss |
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Definition
| traveling wave; precisely |
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Term
-In ___, renaissance man extraordinaire Thomas Gold concluded that the resonant mechanisms proposed by von Helmholtz and the traveling wave of von Békésy were both components of the cochlear analyzer
-Gold postulated an oscillating ___ mechanism that should be audibly perceptible |
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Definition
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Term
-In 1978 British scientist David Kemp reports measurement of ____ emissions from the ear.
-In 1979, Kemp describes similar emissions produced ___ (without a stimulus) |
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Definition
| stimulated (evoked); spontaneously |
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Term
| A new auditory phenomenon has been identified in the acoustic impulse of the human ear…This component of the response appears to have its origin in some ___ mechanism probably located in the cochlea, responding mechanically to auditory stimulation, and dependent upon the normal functioning of the cochlea ___ process…It is tempting to suggest that one of the functions of the outer hair cell population is the generation of this ___ energy |
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Definition
| nonlinear; transduction; mechanical |
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Term
In 1982, Scandinavian scientists N.J. Johnsen and colleagues
describe ____ OAEs |
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Definition
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Term
-In 1983, Hallowell ___ describes the “cochlear amplifier” and speculates (correctly, as it turns out) on the origin of OAE signals
-In 1985, American audiologist William ___ describes outer hair cell motility |
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Definition
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Term
| What is the source of the energy for the cochlear amplifier? The best hint that we have is the requirement that the outer hair cells be ___. This suggests a ___ function for OHC, with the efferent innervation providing a modulating influence, and perhaps a trophic function also. The large number of OHCs, ___ rows instead of one, may be an expression of the need for a large source of ___. |
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Definition
| intact; motor; three; power |
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Term
-OAEs are believed to be by-products of the ___ ___
-No ___ involvement-Can be measured even when neural responses are ___ or when ___ nerve transmission is blocked
-Related to normal functioning of OHC-____ to agents known to affect OHC function
-Affected by alterations to the ___ innervation systems of OHC-Contralateral suppression, direct electrical stimulation of ___ fibers appear to affect OAE amplitude |
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Definition
| cochlear amplifier; neural; absent; VIII; Vulnerable; efferent; efferent |
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Term
-In 1989, F.P. Harris, Brenda Lonsbury-Martin and colleagues at Baylor University systematically study ___ of distortion tones on DPOAE
-In 1992, American hearing scientist Peter ___ describes threshold sensitivity and frequency tuning of the outer hair cells |
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Definition
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Term
| You want 2 frequencies that are close together but not ___ ___, which is why f1 and f2 are separated by a ratio of ___. You don't want the 2 tones to look like ___ big peak, you want 2 ___ peaks. |
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Definition
| too close; 1.22; one; separate |
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Term
Spontaneous OAEs:
-No ___ needed
-Present in less than ___% of humans. Comparable prevalence in newborns, children, and adults
-More common in ___ than in ___.
-No clear effect of ___ if hearing sensitivity is normal.
-Frequencies tend to be stable over ___ periods of time. ___ frequencies are common. Amplitudes may ___ (e.g., middle ear effects)
-Independent of ___ |
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Definition
| stimulus; 70; females; males; aging; long; Multiple; fluctuate; tinnitus |
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Term
Transient Evoked OAEs (TEOAE):
-Measured following introduction of a ___ stimulus – click or tone burst
-Evaluated in terms of ___, ___, and ___
-___ in nearly all ears with normal sensitivity and ME function
-ABSENT in nearly all ears with SNHL greater than __-__ dB HL |
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Definition
transient (brief); amplitude; reproducibility; SNR; PRESENT; 30-50
[image] |
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Term
Distortion Product OAEs (DPOAE):
-Non-linear distortion produced by simultaneous introduction of tones at certain ___ ___
-When f1 and f2 are close in frequency, they interact to produce energy at predictable ___ ___ |
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Definition
| frequency ratios; discrete frequencies |
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Term
| What are some clinical applications of OAEs? |
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Definition
| noise/music exposure, monitor ototoxicity, assess suspected functional hearing loss, cochlear vs retrocochlear, CAPD, hearing screenings, assessment of tinnitus and hyperacusis, newborn hearing screening |
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Term
| What are some advantages of OAEs? |
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Definition
| doesn't require behavioral response, sensitive to OHC function, ear and frequency specific, can be sedated or asleep, no sound booth, good cross check, can be quick, portable, and relatively inexpensive |
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Term
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Definition
| can be affected by noise, affected by ME disorder, doesn't provide info about IHC, can be abnormal with normal audiogram and vice versa, aren't detectable with HL >30-50 dB HL, not a true test of hearing, and doesn't measure neural auditory function |
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Term
Probe Components:
-DPOAE: ___ tubes. ___ stimulus drivers (f1 and f2), microphone
-TEOAE: ___ tubes. ___ stimulus driver (transient), microphone |
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Definition
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Term
Components of the OAE System:
-Stimulus components: ___ generator, ____ circuitry, and ___
-Measurement components: ___, Band-pass filter (Isolate energy at expected DP frequencies), ___, and Analog-to-digital converter which is housed in a computer or stand-alone device |
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Definition
| Signal; Amplifier/attenuator; Speaker; Microphone; Amplifier; |
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Term
-OAEs are VERY ___-intensity signals
-As a result, OAE devices require extensive ___ of the signal to extract the response from the noise floor |
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Definition
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Term
| What are some sources of noise? |
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Definition
| microphone noise, ambient noise in the test setting, breathing, rubbing of the probe tube against clothing, jaw movements, muscle movements, and blood flow |
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Term
Time-synchronous averaging:
-Each time the stimulus is presented, the ___ in the ear canal is sampled
-Starting point of the sample is ___ with the onset of the stimulus
-Stimulus presented hundreds of times, with the sample averaged across each ___ |
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Definition
| sound; synchronized; presentation |
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Term
Averaging:
-Assumption: each time the OAE is sampled, it should be the ___
-Therefore, any noise or artifact that does not recur in synch
with the stimulus is noise, which will be random and eventually will ___ out |
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Definition
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Term
| What are some actions you can take to minimize the noise effects on OAE recordings? |
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Definition
-eliminate extraneous noise sources in test room
-close door to test room
-insert probe deeply
-secure probe cord
-instruct patient to remain quiet and still (if feasible)
-position test ear away from equipment
-modify protocol (to frequencies > 2000 Hz) |
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Term
| Are there ANSI standards for OAEs? |
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Definition
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Term
| How often should OAE units be checked? |
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Definition
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Term
OAE Calibration-Frequency:
-An electronic counter can be used to determine whether probe signals for distortion-product OAEs are ___ in terms of ___ |
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Definition
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Term
OAE Calibration-Intensity:
-In many cases, the OAE probe may be coupled to a 2-cc coupler (HA-type) and sound level meter with octave band filter to measure ___ and check for ___
-For DPOAE, each stimulus channel must be measured ___
-For TEOAE, SLM must be able to sample ___ noises |
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Definition
| intensity; distortion; independently; impulse |
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