06c: Peripheral Auditory System Flashcards
Perceived loudness of sound reflects (X).
X = amplitude of pressure fluctuations
The Sound Pressure Level (SPL) is defined as:
20*log(P/Po)
SPL has which units?
dB
If the pressure of a sound wave is 100 times greater than reference level, the intensity would have which value?
SPL = 20*log(100) = 40 dB
For every increase in pressure by one order of magnitude, the intensity we perceive is increased by:
20 dB
Perceived pitch of sound reflects (X).
X = frequency
Frequency units.
Hz
Explain reason for “impedance mismatch” in (X) system?
X = auditory;
Air is less dense than inner ear fluid, so most E from incoming sound wave would be reflected back upon reaching interface
The (X) system overcomes “impedance mismatch” because (Y) is (Z) times greater than:
X = auditory; Y = ear drum/tympanic membrane Z = 20
Oval window/footplate of Stapes
Since the tympanic membrane’s surface area is so much larger than (X), the (Y) is amplified correspondingly.
X = oval window Y = force per unit area
The orientation and movement of middle ossicles bones provides (X) advantage factor of (Y).
X = mechanical; Y = 1.5
T/F: sound arriving at inner ear through the skull passes the middle ear.
False
Ossicles are present in (external/middle/internal) ear. List them, from lateral to medial.
Middle
- Malleus
- Incus
- Stapes
(X) is the site for transducing sound waves into neural impulses
X = cochlea
Cochlea composed of (X) number of (perpendicular/parallel) canals. List them, from top to bottom.
X = 3
Parallel;
- Scala vestibuli
- Scala media
- Scala tympani
Which canals in cochlea contain perilymph, which is high in (X) ion?
Scala vestibuli and tympani
X = Na
Which canals in cochlea contain endolymph, which is high in (X) ion?
Scala media
X = K
Which canals in cochlea in contact with round window?
Scala tympani