Psych Chapter 4-The auditory system

Question 1

What is sound?

Answer 1

Sound is vibration, a kind of mechanical energy travelling through a medium usually air.

Question 2

What is pitch?

Answer 2

The frequency of the waves. You people are more sensitive to higher pitch tones than older people.

Question 3

What is loudness?

Answer 3

The amplitude of the sound wave measured in decibels (dB).

Question 4

What is timbre?

Answer 4

Refers to the quality or complexity of the sound.

Question 5

What are three parts of the ear?

Answer 5

Outer ear, inner and middle ear.

Question 6

What is the outer ear?

Answer 6

Consists of the pinna and ear canal.

Question 7

What is the pinna?

Answer 7

The part of the ear we see, the skin and cartilage flap.

Question 8

What is the ear canal?

Answer 8

Funnels sound waves onto the eardrum.

Question 9

What is the middle ear?

Answer 9

Lies on the other side of the eardrum, contains the ossicles.

Question 10

What are the ossicles?

Answer 10

Smallest bones in the body, malleus, incus and stapes. The ossicles vibrate at the frequency of the sound wave, transmitting it from the eardrum to the inner ear.

Question 11

What is the inner ear composed of?

Answer 11

The cochlea.

Question 12

What is the cochlea?

Answer 12

Spiral in shape, converts vibration into neural activity, the outer part is bony and the inner cavity is filled with a thick fluid.

Question 13

How does the cochlea transduce?

Answer 13

Vibrations from sound waves disturb the inner fluid of the cochlea and travel to the base of the cochlea, where pressure is released and transduction occurs.

Question 14

What is located in the cochlea?

Answer 14

The organ of Corti and basilar membrane.

Question 15

What is special about the organ of Corti and basilar membrane?

Answer 15

They have hair cells embedded in them.

Question 16

What do hair cells do?

Answer 16

Contain cilia that protrude into the fluid of the cochlea, when sound waves travel through the cochlea, the resulting pressure deflects the cilia, exciting the auditory nerve, which travels to the brain through the thalamus.

Question 17

Describe the auditory pathway.

Answer 17

Once the auditory nerve enters the brain, it makes contact with the brain stem, which sends auditory information higher, all the way up to the auditory cortex.

Question 18

Hair cells located at the base of the basilar membrane are most excited by which kind of tones?

Answer 18

high pitched tones.

Question 19

Hair cells located at the top of the basilar membrane are most excited by which kind of tones?

Answer 19

low pitch tones

Question 20

What is place theory?

Answer 20

Mode of pitch perception. A specific place along the basilar membrane-and in the auditory cortex-matches a tone with a specific pitch. This only accounts for high pitch tones.

Question 21

What are the two routes to perceiving low pitched tones?

Answer 21

Frequency theory and volley theory.

Question 22

What is frequency theory?

Answer 22

The rate at which neurons fire action potentials faithfully reproduces the pitch.
Works well up to the neuronal maximal firing rate, 1000 Hz.

Question 23

What is volley theory?

Answer 23

Variation of frequency theory for tones between 1000 and 5000 Hz. According to volley theory, sets of neurons fire at their highest rate, slightly out of sync with each other to reach overall rates up to 5000 Hz.

Question 24

How does our brain localize sound?

Answer 24

When the auditory nerve enters the brain, some of its axons connect with cells on the same side and others cross over. This allows information from both ears to reach the same structures in the brain stem. The sources of information arrive out of sync (since they take different pathways)Our brains compared the binaural cue to localize sound sources.

Question 25

What is sound shadow?

Answer 25

There’s a difference in loudness between our ears, because the closest to the sound source is in the direct path of the sound wave whereas the other ear is in a sound shadow, created by our head.

Question 26

What are monaural/binaural cues?

Answer 26

Cues from either one or both ears.

Question 27

What is echolocation?

Answer 27

Emit sounds and listen to their echoes to determine their distance from a wall or barrier.

Question 28

What are the causes of deafness?

Answer 28

Genetic, disease, injury, exposure to loud noise.

Question 29

What is conductive deafness?

Answer 29

Due to malfunctioning of the ear, especially of the eardrum or ossicles.

Question 30

What is nerve deafness?

Answer 30

Due to damage to the auditory nerve.

Question 31

What is noise-induced hearing loss?

Answer 31

Loud sounds, especially those that last a long time or are repeated, can damage our hair cells and lead to hearing loss.

Question 32

What is tinnitus?

Answer 32

Associated with noise-induced hearing loss. It’s a ringing, roaring, hissing or buzzing sound in the ears.

Question 33

Attending to music structure requires which hemisphere?

Answer 33

Both.