audio system

Question 1

amplitude

Answer 1

intensity-measured in decibels

Question 2

loudness

Answer 2

is the perception on intensity

Question 3

frequency

Answer 3

the number of compressions per second-measured in hertz (Hz)

Question 4

pitch

Answer 4

is the perception of frequency

hearing range is 15-20,000 Hz for humans

Question 5

Pinna

Answer 5

the structure of flesh and cartilage attached to each side of the head
outer ear

Question 6

Tympanic membrane

Answer 6

mid-ear
(eardrum)
-vibrates at the same frequency as the sound waves that strike it.
-Sound waves reach the tympanic membrane through the auditory canal.
-attached to three tiny bones (hammer, anvil, and stirrup)

Question 7

Hammer (malleus)

Answer 7

a small bone in the middle ear that transmits vibrations of the eardrum to the incus

Question 8

Anvil (incus)

Answer 8

a small anvil-shaped bone in the middle ear, transmitting vibrations between the malleus and stapes.

Question 9

stirrup (stapes)

Answer 9

a bone in the middle ear of humans and other mammals which is involved in the conduction of sound vibrations to the inner ear. The stirrup-shaped small bone is on and transmits these to the oval window, medially. The stapes is the smallest and lightest named bone in the human body, and is so-called because of its resemblance to a stirrup

Question 10

oval window

Answer 10

inner ear

receives vibrations from the tiny bones of the middle ear, and the cochlea

Question 11

cochlea

Answer 11

inner ear

• snail-shaped structure
• contains three fluid-filled tunnels: the scala vestibule, scala media, and scala tympani

Question 12

hair cells

Answer 12

• auditory receptors that lie between the basilar membrane and the tectorial membrane in the cochlear
• vibrations in the fluid of the cochlea displace these
• responds within microseconds to displacements as small as 10^-10 meter, thereby opening ion channels in its membrane
• these cells then stimulate the auditory nerve cells (eighth cranial nerve)

Question 13

basilar membrane

Answer 13

The basilar membrane within the cochlea of the inner ear is a stiff structural element that separates two liquid-filled tubes that run along the coil of the cochlea, the scala media and the scala tympani

Question 14

tectorial membrane (eardrum)

Answer 14

middle ear

it vibrates at the same frequency as the sound wave that strike it

Question 15

Auditory Pathway

Answer 15

cochlea—cochlear nucleus— superior olive—medial geniculate nucleus (thalamus)—auditory cortex (temporal lobe)

Question 16

localization of sounds

Answer 16

1. different intensity between each ear ( work best for frequencies above 2-3,000 Hz)
2. the difference in the time of arrival at each ear
3. phase difference between the ears (see fig 7.9) this works best for low frequencies

Question 17

frequency theory

Answer 17

-we perceive certain pitches when the basilar membrane vibrates in synchrony with a sound, causing the axons of the auditory nerve to produce action potentials at the same frequency
only works for low frequency
up to 100 Hz

Question 18

place theory

Answer 18

-each area along the basilar membrane is tuned to a specific frequency and vibrates whenever the frequency is present. Each frequency activates hair cells at only one place along the basilar membrane, and the brain distinguishes frequencies by which neurons are activated.
-DOWNFALL of this theory: the various parts of the basilar membrane are bound together too tightly for any part to resonate like a piano string
4,000 Hz to 20,000 Hz

Question 19

volley principle of pitch discrimination (mechanism)

Answer 19

the auditory cortex as a whole can have volleys of impulses to about 4000 per second

Question 20

conductive deafness (middle-ear)

Answer 20

occurs if the bone of the middle ear do not transmit sound waves properly. Causes include diseases, infections,m tumors…

Question 21

Nerve deafness (inner-ear deafness)

Answer 21

results from damage to the cochlea, hair cells or the auditory nerve. cause include German measles and other diseases during pregnancy, lack of oxygen at birth, inadequate activity of thyroid gland, multiple sclerosis, meningitis, reaction to aspirin (children), and repeated expose to loud noises.

Question 22

tinnitus

Answer 22

a frequent of constant ringing in the ears. More common in the elderly.