Outer Ear

Question 1

2 components of outer ear

Answer 1

pinna and outer ear canal

Question 2

anatomy of pinna

Answer 2

composed of flexible cartilage and covered with skin (except for lobule which is covered with fat)
helix, anti-helix, tragus, lobule

Question 3

anatomy of outer ear canal

Answer 3

oval opening
skin-lined
formed of a soft, cartilaginous outer tube connected to a hard, bony inner tube
“S” shaped –> NOT straight

Question 4

4 functions of outer ear canal

Answer 4

collect sound
sound pressure gain
sound localization
protection of tympanic membrane

Question 5

main function of the pinna

Answer 5

localize sound

Question 6

sound pressure gain

Answer 6

measures changes between sound source and TM

amplifies middle frequencies 1-5 kHz

Question 7

what frequency does the outer ear peak at?

Answer 7

2.5 kHz

Question 8

what frequency does the middle ear peak at?

Answer 8

1 kHz

Question 9

2 cues for sound localization

Answer 9

intensity and phase (time) difference

Question 10

what provides protection of the tympanic membrane?

Answer 10

fine hairs in outer ear canal and cerumen (ear wax)

Question 11

effect of sound pressure gain on the outer ear canal

Answer 11

resonates at 3000 Hz

Question 12

effect of sound pressure gain on tympanic membrane

Answer 12

high impedance at low frequency

low impedance in the 1000-4000 Hz range