Chapter 10: How Do We Hear, Speak, and Make Music?

Question 1

Pathway of information flow in the ear

Answer 1

Auditory system converts physical properties of sound wave energy to electrochemical neural activity that travels to the brain

Question 2

Frequency

Answer 2

cycles per second -> pitch of the sound

Question 3

Amplitude

Answer 3

height of the waves -> loud vs soft

Question 4

Timbre

Answer 4

complexity of the tone -> pure vs mix of frequencies

Question 5

Structure of the ear

Answer 5

1. Pinna catches sound waves in the ear canal
2. Waves amplified and directed to the eardrum
3. Eardrum vibrates the ossicles
4. Ossicles amplify vibrations to the oval window
5. Vibration of oval window sends waves through cochlear fluid
6. Waves cause the basilar and tectorial membranes to bend
7. Membrane bends cause cilia of inner hair cells to bend and generate neural activity towards nerve fibers

Question 6

Where are high frequencies processed on basilar membranes? Low frequencies?

Answer 6

Higher frequencies are processed in the base on the basilar membranes while lower frequencies are processed towards the apex

Question 7

Auditory receptor cells

Answer 7

embedded within the basilar membrane. This membrane divides the spiraled cochlea into upper and lower chambers. Movement of the fluid within the cochlea causes stimulation of the hair cells.

Question 8

Pathway of information flow to the auditory cortex

Answer 8

Cochlear nucleus -> olivary complex -> inferior colliculus -> medial geniculate nucleus -> auditory cortex

Question 9

Tonotopic organization

Answer 9

cells responsive to different frequencies are found in different places at each level of the central auditory system.

Each cell has a characteristic frequency (CF).

Question 10

Interaural intensity and time difference

Answer 10

• The interaural time difference (ITD) is computed in the medial superior olive
• The interaural intensity difference (IID) is computed in the Lateral part of the superior olive and trapezoid body

Question 11

Auditory cortex

Answer 11

the part of the temporal lobe that processes auditory information in humans and many other vertebrates

Question 12

Pathway that connects Wernicke’s area and Broca’s area

Answer 12

Arcuate fasciculus

Question 13

Function of Wernicke’s area

Answer 13

posterior speech area at the rear of the left temporal lobe that regulates language comprehension; also called the posterior speech zone

Comprehension (listen to Dr. Wernicke)

Question 14

Function of Broca’s area

Answer 14

anterior speech area in the left hemisphere that functions with the motor cortex to produce the movements needed for speaking

Speech (speak to me bro)

Question 15

Two types of Aphasia

Answer 15

• Inability to speak or comprehend language despite having normal comprehension or intact vocal mechanisms
• Broca’s -> inability to speak fluently despite having normal comprehension and intact vocal mechanisms

-Wernicke’s aphasia -> inability to understand or produce meaningful language even though the production of words is still intact

Question 16

Neurobiology of birdsong

Answer 16

Higher vocal control center
Nucleus robustus archistriatalis

Question 17

How is speech produced?

Answer 17

produced through the connection that the arcuate fasciculus makes between Wernicke’s area and Broca’s area