AUD 641 Exam 3 With Correct Solution
What is the priniciple behind OAEs? - ANSWER The active processes of the cochlea
How are OAEs generated? - ANSWER 1. Cochlea receives sound energy
2. While amplifying sound energy, cochlea loses control of a small amount of energy
3. Some sound energy is sent back to ME/EC, which is recorded by the microphone
What do OAEs tell us? - ANSWER Indirect measure of health of the cochlea when the
cochlea is stimulated with sound
Why are OAEs an indirect measure? - ANSWER Not a direct measure because we are
not sticking anything directly into the cochlea (like a probe or electrode)
Important OAE History (Potential Bonus):
Who is this? What is the year?
While playing double stop trills (violin), he heard audible notes that he was not playing.
He assumed the ear "filled in" additional tones not played by violin. - ANSWER Guiseppe
Tartini
1700s
Fun Fact: He had 6 fingers.
Tartini Tones = DPOAEs
Important OAE History (Potential Bonus):
Who is this? What is the year?
Cochlea has structural units (resonators) that are individually tuned to different
frequencies - ANSWER Hermann von Helmhotlz
1863
Important OAE History (Potential Bonus):
Who is this? What is the year?
Thought traveling wave was one-way and that the cochlea functioned passively
Never would have found OAEs because work was on cadavers; only living people gave
OAEs - ANSWER Georg von Bekesy
,1928
Important OAE History (Potential Bonus):
Who is this? What is the year?
Believed cochlea was characterized by active processes - ANSWER Thomas GOld
1948
"The Big Cheese"
Important OAE History (Potential Bonus):
Who is this? What is the year?
Discovered OAEs - ANSWER David Kemp
1977
Why did Gold believe cochlea was characterized by "active processes"?
(3) - ANSWER -Cochlear fluids are thick and would reduce resonance abilities of inner
ear
-Thus, the cochlea uses active amplification to enhance resonance of inner ear
Who discovered OAEs and what was the year? - ANSWER David Kemp
1977
What did David Kemp's paper in 1978 say? - ANSWER If tones or clicks are put into the
ear, can measure additional sound in the external ear canal (using a microphone)
How did OAEs evolve after this seminal paper? - ANSWER OAEs became more popular
towards the end of the 1990s
What was the earliest clinical application of OAEs? - ANSWER mid-80s
Newborn Hearing Screenings
Although OAEs are still widely used to screen in infants, what is the major limitation of
using an OAE as a screening tool in infants? - ANSWER It cannot detect auditory
neuropathy spectrum disorder - Best if combined with ABR
By the year 2000, there was plenty of research to support diagnostic value of OAEs.
What is the diagnostic value of OAEs? - ANSWER Assuming that ME function is normal,
OAEs have a unique sensitivity to the damage of OHCs
What are the categories for OAEs? - ANSWER Spontaneous and Evoked
Spontaneous OAEs - ANSWER These OAEs occur in the absence of an external stimuli
,and don't have a lot of clinical value
What are the Evoked OAE types? - ANSWER Stimulus Frequency
Transient
Distortion Product
Stimulus Frequency OAEs
(Least studied experimentally and clinically and are not really used clinically) - ANSWER
elicited by continuous pure tone
Transient OAEs - ANSWER elicited by clicks or short-tone bursts
Distortion Product OAEs - ANSWER Elicited by tone pairs
OAEs are a clinically sensitive measure of _________________ - ANSWER cochlear (OHC)
function
What role do they play clinically? - ANSWER Early identification of auditory dysfunction,
especially with newborn screenings
OAES do NOT measuring hearing sensitivity. Why? - ANSWER Because it is a
physiologic test NOT a behavioral test
However, you may infer their hearing from the health of the cochlea
What are the 4 important regions of the auditory system that either contribute to
generation of OAEs or can influence OAE recording? - ANSWER -External Ear Canal
-Middle Ear System
-Cochlea
-Efferent Auditory System (going from CNS to peripheral auditory system)
What is the resonance peak for adults? - ANSWER Around 2600 Hz or (2.6K Hertz)
(Higher in newborns. Around 2-3 years old it begins to approximates adult values)
Why do you want a really good insertion? - ANSWER How well our probe tip is inserted is
going to effect the quality of our measurements - in order to get results that are as
accurate as possible, we need a good insertion.
You do not need a hermetic seal like tymps. But a snug fit helps with noise.
Placing a probe tip into the EC changes ________________ - ANSWER EC resonance
EC resonance...
Determined by...
, Affecteed by...
Depends on... - ANSWER determined by volume between probe tip and tympanic
membrane
affected by depth of insertion and quality of seal
EC acoustics also depend on shape of the EC
(Straight vs. Curvy) & (Can affect calibration of the stimulus)
Why do newborns have higher OAEs than adults? - ANSWER because of the difference
in resonant characteristics
Besides normal variation in EC geometry... EC acoustics are affected by
_________________________ - ANSWER any debris or pathology in the external EC
List some non pathologics that affect EC acoustics: - ANSWER Cerumen
Debris
Foreign Objects
Vernix Casseosa in Neonates
Vernix Casseosa in Neonates - ANSWER waxy white substance that covers the skin of a
newborn baby
List some Pathologic debris: - ANSWER Stenosis
External Otitis
Cyst
Describe the OAE Probe in External EC - ANSWER 1 or 2 signal delivery tubes that are
connected to miniature speakers
At least 1 microphone to record the acoustic signals in EC
What is the priniciple behind OAEs? - ANSWER The active processes of the cochlea
How are OAEs generated? - ANSWER 1. Cochlea receives sound energy
2. While amplifying sound energy, cochlea loses control of a small amount of energy
3. Some sound energy is sent back to ME/EC, which is recorded by the microphone
What do OAEs tell us? - ANSWER Indirect measure of health of the cochlea when the
cochlea is stimulated with sound
Why are OAEs an indirect measure? - ANSWER Not a direct measure because we are
not sticking anything directly into the cochlea (like a probe or electrode)
Important OAE History (Potential Bonus):
Who is this? What is the year?
While playing double stop trills (violin), he heard audible notes that he was not playing.
He assumed the ear "filled in" additional tones not played by violin. - ANSWER Guiseppe
Tartini
1700s
Fun Fact: He had 6 fingers.
Tartini Tones = DPOAEs
Important OAE History (Potential Bonus):
Who is this? What is the year?
Cochlea has structural units (resonators) that are individually tuned to different
frequencies - ANSWER Hermann von Helmhotlz
1863
Important OAE History (Potential Bonus):
Who is this? What is the year?
Thought traveling wave was one-way and that the cochlea functioned passively
Never would have found OAEs because work was on cadavers; only living people gave
OAEs - ANSWER Georg von Bekesy
,1928
Important OAE History (Potential Bonus):
Who is this? What is the year?
Believed cochlea was characterized by active processes - ANSWER Thomas GOld
1948
"The Big Cheese"
Important OAE History (Potential Bonus):
Who is this? What is the year?
Discovered OAEs - ANSWER David Kemp
1977
Why did Gold believe cochlea was characterized by "active processes"?
(3) - ANSWER -Cochlear fluids are thick and would reduce resonance abilities of inner
ear
-Thus, the cochlea uses active amplification to enhance resonance of inner ear
Who discovered OAEs and what was the year? - ANSWER David Kemp
1977
What did David Kemp's paper in 1978 say? - ANSWER If tones or clicks are put into the
ear, can measure additional sound in the external ear canal (using a microphone)
How did OAEs evolve after this seminal paper? - ANSWER OAEs became more popular
towards the end of the 1990s
What was the earliest clinical application of OAEs? - ANSWER mid-80s
Newborn Hearing Screenings
Although OAEs are still widely used to screen in infants, what is the major limitation of
using an OAE as a screening tool in infants? - ANSWER It cannot detect auditory
neuropathy spectrum disorder - Best if combined with ABR
By the year 2000, there was plenty of research to support diagnostic value of OAEs.
What is the diagnostic value of OAEs? - ANSWER Assuming that ME function is normal,
OAEs have a unique sensitivity to the damage of OHCs
What are the categories for OAEs? - ANSWER Spontaneous and Evoked
Spontaneous OAEs - ANSWER These OAEs occur in the absence of an external stimuli
,and don't have a lot of clinical value
What are the Evoked OAE types? - ANSWER Stimulus Frequency
Transient
Distortion Product
Stimulus Frequency OAEs
(Least studied experimentally and clinically and are not really used clinically) - ANSWER
elicited by continuous pure tone
Transient OAEs - ANSWER elicited by clicks or short-tone bursts
Distortion Product OAEs - ANSWER Elicited by tone pairs
OAEs are a clinically sensitive measure of _________________ - ANSWER cochlear (OHC)
function
What role do they play clinically? - ANSWER Early identification of auditory dysfunction,
especially with newborn screenings
OAES do NOT measuring hearing sensitivity. Why? - ANSWER Because it is a
physiologic test NOT a behavioral test
However, you may infer their hearing from the health of the cochlea
What are the 4 important regions of the auditory system that either contribute to
generation of OAEs or can influence OAE recording? - ANSWER -External Ear Canal
-Middle Ear System
-Cochlea
-Efferent Auditory System (going from CNS to peripheral auditory system)
What is the resonance peak for adults? - ANSWER Around 2600 Hz or (2.6K Hertz)
(Higher in newborns. Around 2-3 years old it begins to approximates adult values)
Why do you want a really good insertion? - ANSWER How well our probe tip is inserted is
going to effect the quality of our measurements - in order to get results that are as
accurate as possible, we need a good insertion.
You do not need a hermetic seal like tymps. But a snug fit helps with noise.
Placing a probe tip into the EC changes ________________ - ANSWER EC resonance
EC resonance...
Determined by...
, Affecteed by...
Depends on... - ANSWER determined by volume between probe tip and tympanic
membrane
affected by depth of insertion and quality of seal
EC acoustics also depend on shape of the EC
(Straight vs. Curvy) & (Can affect calibration of the stimulus)
Why do newborns have higher OAEs than adults? - ANSWER because of the difference
in resonant characteristics
Besides normal variation in EC geometry... EC acoustics are affected by
_________________________ - ANSWER any debris or pathology in the external EC
List some non pathologics that affect EC acoustics: - ANSWER Cerumen
Debris
Foreign Objects
Vernix Casseosa in Neonates
Vernix Casseosa in Neonates - ANSWER waxy white substance that covers the skin of a
newborn baby
List some Pathologic debris: - ANSWER Stenosis
External Otitis
Cyst
Describe the OAE Probe in External EC - ANSWER 1 or 2 signal delivery tubes that are
connected to miniature speakers
At least 1 microphone to record the acoustic signals in EC
