Sound (Audition)

Question 1

Need

Answer 1

pressurized sound wave and hair cell. Ex: in between hands are a bunch of air molecules, and suddenly hands move towards each other, so space is a lot smaller

Question 2

Sounds waves

Answer 2

air molecules are pressurized and try to escape, creating areas of high and low pressure
-can be far apart or close together
-how close peaks are is the frequency
-different noises have different sounds

Question 3

Different frequencies

Answer 3

Listen at same time- if you add different frequency waves together, get weird frequency. Ear has to break this up. Able to do that because sound waves travel different lengths along cochlea

Question 4

Hair cells

Answer 4

first hit outer part of ear (pinna), then goes to external auditory meatus (auditory canal), then hits the tympanic membrane (eardrum)

Question 5

Malleus, incus, and stapes

Answer 5

pressurized waves hits eardrum, it vibrates back and forth and makes these 3 bones vibrate

Question 6

Stapes

Answer 6

attached to oval window and as it gets pushed, it pushes fluid to go around the cochlea. At tip of cochlea, it only goes back and goes to the round window and pushes it out

Question 7

Organ of corti

Answer 7

reason it doesn’t go back to oval window, because of Organ of Corti (includes basilar membrane and tectorial membrane)

Question 8

General classification

Answer 8

from pinna to tympanic membrane is the outer/external ear, from malleus to stapes: middle ear, and cochlea and semicircular canals is the inner ear

Question 9

Stapes

Answer 9

moves back and forth at same frequency as stimulus, pushes elliptical window back and forth. Fluid inside cochlea which gets pushed around cochlea and comes back around. Organ of Corti splits cochlea into 2

Question 10

Cross Section of Organ of Corti

Answer 10

-upper and lower membrane, and little hair cells and as fluid flows around the organ it causes hair cells to move back and forth
-the hair bundle is made of little filaments and each filament is called a kinocilium
-tip of each kinocilium is connected by a tip link
-tip link attached to gate of K channel, so when get pushed back and forth they stretch and allows K to flow inside the cell
-Ca cells get activated when K is inside, so Ca also gets activated and causes AP in a spiral ganglion cell which then activates the auditory nerve

Question 11

Cochlea

Answer 11

brain relies on this to differentiate between 2 different sounds

Question 12

Basilar tuning

Answer 12

there are varying hair cells in cochlea and hair cells at base of cochlea are activated by high frequency sounds and those at apex by low frequency sounds.
Apex- 25 Hz and base= 1600 Hz

Question 13

Primary auditory cortex

Answer 13

only certain hair cells are activated and send AP to the brain and this receives all info from cochlea
-also sensitive to various frequencies in different locations

Question 14

Tonotypical mapping

Answer 14

with basilar tuning brain can distinguish different frequencies

Question 15

Sensory narrow hearing loss

Answer 15

surgical procedure that attempts to restore some degree of hearing to individuals- nerve deafness
-problem with conduction of sound cochlea to brain

Question 16

Receiver/stimulator/transmitter/speech processor

Answer 16

receiver goes to stimulator which reaches the cochlea. Receiver receives info from a transmitter. Transmitter gets electrical info from the speech processor and speech processor gets info from microphone

Question 17

Pathway

Answer 17

sound–> microphone–>transmitter (outside the skull) sends info to the receiver (inside). Then sends info to the stimulator, into the cochlea and cochlea converts electrical impulse into neural impulse that goes to the brain