Lecture 8 - Audition

Question 1

What are the steps on the auditory pathway?

Answer 1

cochlear nucleus (starting point) –> superior olivary complex –> lateral lemniscus—-> inferior colliculi—>medial lemniscus—-> auditory cortex (A1)

Question 2

How many auditory fields are in each ear?

Answer 2

Two

Question 3

What are the two ways that human beings localize sound?

Answer 3

frequency and intensity

Question 4

Which section of the auditory system do humans detect speech?

Answer 4

parabelt (i.e., the secondary auditory cortex or A2)

Question 5

Which section of the auditory system do humans detect sounds (include their frequencies and intensities)?

Answer 5

Core (i.e., Heschl gyrus or Brodmann area 41 or the primary auditory cortex A1)

Question 6

What does the parabelt and belt consist of?

Answer 6

belt = Wernicke’s area (Auditory association 2 or Brodmann area 42 ), Brodmann areas 39, inferior parietal lobule, anterior superior temporal gyrus, posterior temporal gyrus, parietal and temporal bords, Brodmann area 22, and the entire superior, middle, and inferior temporal gyrus

Question 7

What is ABR? What does it do?

Answer 7

Auditory Brain Response - a test to determine if the cochlea is functioning properly; it records brain waves that respond to sounds heard through earphones.

Question 8

In ABR, auditory middle latency ERP (Evoked Response Potentials) refers to

Answer 8

P 20-50 ms- thalamus - medial geniculate nucleus

Question 9

What are signs that there is a lesion in the medial geniculate nucleus?

Answer 9

no effect indicated on the speech recognition test; opposite ear has poorer hearing based on the dichotic listening test; ABR is normal/ no effect; indications of middle and late potentials (i.e., auditory info has reached the thalamus)

Question 10

What is the first site of crossover in the auditory pathway?

Answer 10

At the superior olivary complex

Question 11

What is the crossover of auditory information?

Answer 11

sound information is carried on both sides of the pathway

Question 12

What is the function of the inferior colliculus?

Answer 12

locates sound, determines frequency, and combines auditory systems with nonauditory systems

Question 13

Which part of the auditory system is there only unilateral representation of sound in the CNS?

Answer 13

cochlear nuclei

Question 14

What is the medial geniculate nucleus?

Answer 14

nuclei found in the thalamus that sends binaural information from the inferior colliculus to the auditory cortex. It has polysensory neurons.

Question 15

What parts of the brain does the medial geniculate nucles receive information from?

Answer 15

inferior colliculus and pontine reticular

Question 16

What locations of the brain may the medial geniculate nucleus send auditory information to?

Answer 16

auditory cortex and pulvinar nuclei of the thalamus

Question 17

What is the pulvinar nuclei of the thalamus known for?

Answer 17

associated with attention

Question 18

What is the perisylvian fissure important for?

Answer 18

taking what humans hear and perceiving it as phonemes

Question 19

What is one fact about the auditory core cortex?

Answer 19

There is more than one space that responds to different tones and in different orders. There are many representations of frequency in each area of the auditory core cortex.

Question 20

What are signs that there’s a lesion at the superior olivary complex?

Answer 20

pure tone test and speech recognition test are both within normal limits; masking difference levels (tests sound localization) is poor, in ABR a wave is delayed; sound localization is poor in both auditory fields

Question 21

What are signs that there’s a lesion at the medial geniculate nucleus?

Answer 21

speech recognition test is within normal limits; dichotic listening test is poorer in the right ear, frequency patterns (non-speech) poor in both ears; ABR is WNL

Question 22

The planum temporale is larger in which hemisphere and is found where?

Answer 22

left hemispehere, belt portion

Question 23

Who diagnoses someone with APD or auditory processing disorder? What should an evaluation of someone suspected to have APD include?

Answer 23

audiologists; it should include verbal and nonverbal tests

Question 24

Selective attention to sounds occurs at the _____ and ______

Answer 24

thalamus (pulvinar nuclei) and inferior colliculi

Question 25

Cochlear nuclei are found in the ______

Answer 25

medulla

Question 26

The retrocochlear pathway consists of _____

Answer 26

hair cells –> bipolar cells in spiral ganglion —-> through central processes to form acoustic branch (this is CN VIII) —> cochlear nuclei in the medulla

Question 27

The inferior colliculus is found in the _____

Answer 27

midbrain

Question 28

The geniculocortical fibers are found in the ______

Answer 28

internal capsule

Question 29

What part of the brain sends much information to the inferior colliculus?

Answer 29

cerebellum

Question 30

The cochlear nuclei sends auditory information to the ______

Answer 30

superior olivary complex contralaterally

Question 31

The superior olivary complex sends information via _______ ipsilaterally and contralaterally to ___, ___, and ___. It has both excitatory and inhibitory neurons.

Answer 31

olivocochlear bundle; cochlear nuclei, cochlea, and CN VIII

Question 32

To coordinate head and neck and to establish equilibrium, the inferior colliculi communicates with the superior colliculi via _____

Answer 32

CN III (oculomotor)

Question 33

To coordinate head and neck and to establish equilibrium, the superior olivary complex communicates with the medial longitudial nerve via _____

Answer 33

CN IV (trochlear) and CN VI (abducens)

Question 34

To coordinate head and neck and to establish equilibrium, the auditory and vestibular branches of _____ communicate with the ______

Answer 34

CN VIII; cerebellum

Question 35

Neurons in both the ____ and ____ are sensitive to differences in time and frequency.

Answer 35

superior olivary complex and cochlea

Question 36

Sound shadow affects ______ sounds.

Answer 36

high frequency sounds; makes them softer

Question 37

Sound shadow does not affect ____ sounds

Answer 37

low frequency

Question 38

Time difference impacts ______ sounds

Answer 38

low frequency

Question 39

A monaural hearing loss is caused by a lesion to the

Answer 39

Auditory nerve (CN VIII)