Psych 256 Audition lecture

Question 1

What are the three main dimensions of sound (what are their names and stimulus features)?

Answer 1

-pitch: frequency measured in Hz
-loudness: amplitude, measured in dB
-timbre: complexity, measured by fundamental frequency and overtones

Question 2

• What is a Fourier transform (FT)?

Answer 2

-Complex sounds can be broken down into a series of pure tones with a math technique known as
Fourier Transform

Question 3

Describe the pathway sounds take into the ear.

Answer 3

-pinna catches sound waves and deflects them into external ear canal, waves amplified and directed to eardrum causing it to vibrate which in turn vibrates ossicles, ossicles amplify and convey vibrations to the oval window, vibration of oval window send waves through cochlear fluid causing the basilar and
tectorial membranes to bend which in turn cause cilia of our hair cells, embedded in the tectorial
membrane, to bend, this bending generates neural activity in hair cells

Question 4

What is the tympanic membrane?

Answer 4

-tympanic membrane is the eardrum, separates outer ear from middle ear

Question 5

What is the ossicles?

Answer 5

-ossicles is 3 bones in either middle ear that serve to transmits sound from air to cochlea

Question 6

What is the oval window?

Answer 6

-oval window is membrane covered opening from middle ear to cochlea of inner ear

Question 7

What is the cochlea?

Answer 7

-the cochlea is a fluid filled spiral shaped cavity found in the inner ear that plays vital role in sense of
hearing

Question 8

What is the organ of corti?

Answer 8

-the organ of corti is organ of the inner ear located within cochlea

Question 9

What 3 brain areas make up the final pathway sound takes after it leaves the cochlea?

Answer 9

-projects to inferior colliculus > medial geniculate nucleus >primary auditory cortex

Question 10

Where is the insula and what kind of information is processed there?

Answer 10

-auditory cortex is buried within lateral fissure in an area known as insula it helps mediate taste, pain,
language, and social cognition

Question 11

Describe the left/right hemispheric differences associated with auditory processing.

Answer 11

-for right handers, heschls gyrus is larger on the right while the area caudral to it- the planum temporale
or wernickes area is larger on the left

Question 12

What is place coding? Tonotopic representation?

Answer 12

-place coding means that where (the place) receptor activity occurs on A1 determines what kind of
sound is hear
-tonotopic representation is the consistent relation between basilar membrane displacement and
cortical response

Question 13

What is the main mechanism used to determine the location of a sound?

Answer 13

-one of the interaural time difference- difference in the arrival time of a sound to the two ears
-another is head turning or tilting

Question 14

Where are Broca’s and Wernicke’s areas? What are the types of aphasia associated with damage to
these areas? What is the name of the white-matter pathway that connects them?

Answer 14

-speech recognition is related to hearing and mediated by sound images of words stored in the superior
temporal lobe “Wernicke’s area”
-thought processes activate sound images in Wernicke’s area which then project to Broca’s area via
arcuate fasciculus
-damage to Broca’s area produces expressive aphasia (difficulties in producing speech) while damage to
Wernicke’s area produces receptive aphasia (comprehension difficulties)

Question 15

What is amusia?

Answer 15

-amusia is the inability to hold a tone, distinguish pitch (tones), and recognize, produce, or reproduce
melodies (tone deafness)