auditory and vestibular systems

Question 1

4 properties of waves

Answer 1

• amplitude (loudness)
• frequency (pitch)
• phase (location)
• waveform (complex qualities)

Question 2

spectrogram

Answer 2

graph of the power in each frequency band as a function of time

Question 3

formants

Answer 3

energy in different frequency bands

Question 4

pinna

Answer 4

reflects sounds to aid in vertical sound source localization

Question 5

tympanum (ear drum)

Answer 5

vibrates in response to sounds

Question 6

ossicles (three bonds in middle ear)

Answer 6

conduct vibration from eardrum to cochlea
- amplify vibrations in the fluid filled cochlea

Question 7

cochlea

Answer 7

organ which converts vibration into electrical signals

Question 8

cochlear nerve

Answer 8

primary auditory nerve, carries sound info to the brain

Question 9

semicircular canals

Answer 9

primary sense organs for vestibular sensation

Question 10

base resonates to

Answer 10

high frequencies

Question 11

apex resonates to

Answer 11

low frequencies

Question 12

neural encoding of vibration

Answer 12

inner hair cells are innervated by the dendrites of cells in the spiral ganglion
axons of spiral ganglion cells form the auditory nerve carrying auditory info to the brain

Question 13

ascending auditory pathway

Answer 13

auditory signals are passed from the cochlea via to auditory nerve to the cochlear nuclei -> superior olivary nuclei and the inferior colliculus (extracts the spatial info of the sound) -> medial geniculate nucleus of the thalamus -> auditory cortex

Question 14

horizontal localization

Answer 14

done by coincidence detection of signals from the cochlea in the medial superior olive (MSO) - sensitive to differences in timing on the order of microseconds

Question 15

vertical localization

Answer 15

interpreting the characteristics of sound reflected off of the pinna

Question 16

primary auditory cortex is located

Answer 16

on the superior bank of the temporal lobe

Question 17

wernickes area

Answer 17

responsible for understanding the meaning of speech sounds
- patients with damage to this area can neither speak intelligibly nor comprehend spoken language

Question 18

descending control of cochlea

Answer 18

descending axons from the superior olivary nucleus send axons selectively to outer hair cells. the axons hyperpolarize hair cells via ACh. they have an inhibitory influence on cochlear output
- by reducing the sensitivity to loud sounds, this may increase the dynamic range of cochlea and protect from damage from loud sounds

Question 19

dynamic range

Answer 19

the range btw the softest and loudest possible sounds which can be represented by a particular neuron

Question 20

when cells depolarize, hair cells

Answer 20

shorten

Question 21

when cells hyperpolarize, hair cells

Answer 21

elongate

Question 22

otoacoustic emission

Answer 22

when active amplification via outer hair cells cause vibration of the cochlear membrane even without external input

Question 23

hearing loss is caused by

Answer 23

• infection of inner ear
• ototoxic drugs
• ageing
• trauma (loud noises)

Question 24

tinnitus

Answer 24

ringing sensation that follows trauma or other damage to the auditory system

Question 25

otolith

Answer 25

utricle and saccule
respond to linear acceleration

Question 26

semicircular canals

Answer 26

respond to rotational acceleration

Question 27

vestibular-ocular reflex

Answer 27

stabilizes retinal image by moving eyes to compensate for head movement