Chapter 7: AUDITION

Question 1

Speed of noise?

Answer 1

1200 km per hour

Question 2

three dimensions of sound?

Answer 2

• pitch
• loudness
• timbre

Question 3

pitch?

Answer 3

• frequency of vibration

- measured in hertz

Question 4

loudness?

Answer 4

intensity

Question 5

timbre?

Answer 5

complexity

Question 6

How does sound travel through the outer ear?

Answer 6

pinna–>tympanic membrane (eardrum)

Question 7

components of middle ear?

Answer 7

• ossicles
• malleus (hammer)
• incus (anvil)
• stapes (stirrup)
• oval window

Question 8

ossicles?

Answer 8

• bones of the middle ear

- set into vibration by the tympanic membrane

Question 9

malleus?

Answer 9

-transmits vibration via the incus and stapes to the cochlea

Question 10

cochlea?

Answer 10

• liquid-filled
• sound transmitted through air is transferred to cochlea
• divided into three sections (see paper)

Question 11

organ of Corti?

Answer 11

• receptive organ

- consists of basiliar membrane, hair cells, tectorial membrane

Question 12

How does the basiliar membrane respond to sound’

Answer 12

• bends
• high frequency: base of the membrane bends
• low frequency: apex of the membrane bends

Question 13

How is auditory information transmitted to the brain by hair cells?

Answer 13

• Hair cells form synapses with dendrites of neurons whose axons bring auditory info to the brain
• tension on tip links open ion channels, membrane depolarizes, hair cells release neurotransmitters.

Question 14

cochlear nerve?

Answer 14

The branch of the auditory nerve that transmits auditory information from the cochlea to the brain.

Question 15

superior olivary complex?

Answer 15

group of nuclei in the medulla; involved with auditory functions, including localization of the source of sounds

Question 16

lateral lemniscus?

Answer 16

• bundle of fibers
• run rostrally through medulla and pons
• carries fibers of the auditory system

Question 17

tonotopic representation?

Answer 17

-topographically organised mapping of different frequencies of sound that are represented in a particular region of the brain

Question 18

core region?

Answer 18

• The primary auditory cortex

- located on a gyrus on the dorsal surface of the temporal lobe

Question 19

belt region?

Answer 19

• first level of auditory association cortex

- surrounds the primary auditory cortex

Question 20

parabelt region ?

Answer 20

• second level of auditory association cortex

- surrounds the belt region

Question 21

anterior stream of the auditory association cortex?

Answer 21

• complex sounds

- begins in anterior parabelt region

Question 22

posterior stream of the auditory association cortex?

Answer 22

• localization of sound

- begins in the posterior parabelt region.

Question 23

place code?

Answer 23

• moderate to high frequencies

- info about diff frequencies is coded by diff locations on the basiliar membrane.

Question 24

rate code?

Answer 24

• low frequencies

- info about diff frequencies is coded by the rate of firing of neurons in the auditory system.

Question 25

cochlear implant?

Answer 25

-electronic device surgically implanted in the inner ear that can stimulate the basilar membrane

Question 26

How is loudness perceived?

Answer 26

• cochlear nerve alters rate of firing
• produces more intense. vibration so more intense shearing force on the cilia
• more nt release

Question 27

How is the loudness of low frequency perceived?

Answer 27

-signaled by the number of axons arising from the neurons in the basilar membrane

Question 28

fundamental frequency?

Answer 28

• aspect of timbre
• Lowest and usually most intense, frequency of a complex sound
• most often perceived as the sound’s basic pitch

Question 29

overtone?

Answer 29

• aspect of timbre

- frequency of complex tones that occurs at multiples of the fundamental frequency

Question 29

overtone?

Answer 29

• aspect of timbre

- frequency of complex tones that occurs at multiples of the fundamental frequency

Question 30

What does the auditory cortex do in the perception of timbre?

Answer 30

-the auditory cortex analyses a complex sequence of multiple frequencies that appear, change in amplitude, and disappear.

Question 31

phase differences?

Answer 31

• low frequencies

- the diff in arrival times of sound waves at each of the eardrums

Question 32

intensity difference?

Answer 32

• high frequencies

- the difference in sound intensities at each of the eardrums.

Question 33

analysis of timbre?

Answer 33

• to determine the height and if it is in front or behind us

- angle of sound waves striking the folds and ridges of outer ear.

Question 34

perception of identity?

Answer 34

• one pattern of recognition

- activated in the anterior stream

Question 35

perception of location?

Answer 35

• one pattern recognition

- activated in the posterior stream