Auditory

Question 1

audiogram

Answer 1

sound “area” of hearing

Question 2

smallest bone in the body

Answer 2

stapes

Question 3

smallest muscle in the body

Answer 3

stapedius

Question 4

reference pressure

Answer 4

corresponds to threshold; lowest sound pressure normal hearing adults can detect

Question 5

presbycusis

Answer 5

high frequency hearing loss with aging

Question 6

severe hearing loss

Answer 6

~45dB

Question 7

spectrum

Answer 7

pattern of sound frequency

Question 8

3 parts of ear

Answer 8

outer ear, middle ear, inner ear

Question 9

outer ear

Answer 9

pinna – like a funnel; amplifies the sound

Question 10

middle ear

Answer 10

• deep to tympanic membrane
• contains 3 ossicles
• muscles: stapedius and tensor tympanii

Question 11

goal of middle ear

Answer 11

• overcome “problem”

- cochlea filled with fluid

Question 12

Impedence mismatch

Answer 12

g

Question 13

conductive loss

Answer 13

• mechanical type of hearing loss
• many subtypes
• example: otitis media with inclusion; obstruction of canal with mass and limits motion of tympanic membrane

Question 14

Perilymph

Answer 14

high Na, low K; in Scala vestibule and scala tympani

Question 15

Endolymph

Answer 15

High K+, low Na; in scala media

Question 16

Endocochlear potential

Answer 16

powers transduction of sound energy into electrical activity

Question 17

congenital hearing loss

Answer 17

due to collapse of endocochlear potential

Question 18

characteristic frequency

Answer 18

frequency at which threshold the lowest

Question 19

Intensity

Answer 19

encoded by rate at which auditory nerve fibers fire APs

- louder sound – more action potentials

Question 20

auditory neuropathy

Answer 20

problem with transmission of info from hair cells to auditory nerve

• pts present with normal or near-normal audiogram and OAEs but abnormal or absent Auditory brainstem responses (ABRs)
• have difficulty with speech and temporal processing)

Question 21

Prosthetic devices

Answer 21

hearing aid, middle ear implant, cochlear implant, bone-anchored hearing aid

Question 22

middle ear implant

Answer 22

• transducers that vibrate vesicular chain

- implanted in ear

Question 23

cochlear implant

Answer 23

• bypass acoustic conductive apparatus of external//inner ear
• stimulate electrically by array of electric contacts implanted into cochlea
• trying to stimulate auditory nerve fiber using htis principle

Question 24

3 main acoustical cues to location

Answer 24

interaural time delay (ITD), interaural level of differences (ILD), spectral cues (>5kHz)

Question 25

Duplex theory of sound

Answer 25

Low frequencies- ITDs | High frequencies - ILDs

Question 26

Tonotopic organization

Answer 26

as nerve fibers preserve topographic mapping of sound frequency in all neural structures so that adjacent neurons sensitive to slightly different adjacent sound frequencies

Question 27

parallel processing

Answer 27

one common input separated into pieces | - starts in cochlear nucleus

Question 28

Subnuclei of cochlear nucleus

Answer 28

Dorsal Cochlear Nucleus, anteroventral cochlear nucleus, posterovenral cochlear nucleus

Question 29

Coincidence model in the Medial Superior Olive (Jeffress model)

Answer 29

afferent projections keeping track of timing, delay lines created by different lengths of axons projecting to medial superior olive, neurons with property of coincidence detection - acoustic timing delay if sound from one side - only occurs in low frequencies less than 1500 Hz

Question 30

Auditory part of thalamus

Answer 30

medial geniculate

Question 31

primary cortex is in which Broadmann area?

Answer 31

41

Question 32

Wernicke's area

Answer 32

important for speech comprehension; in Secondary auditory cortex

Question 33

Broca's area

Answer 33

Broadmann's area 44/45; if problem with this area, can understand but not produce speech?