chapter 10 - Hearing Flashcards
(35 cards)
what is the amplitude
height of the wave
what is the frequency?
how often one cycle occurs
a tuning fork produces a ____ tone
pure
what is a pure tone
1 sine wave
-no harmonics
-no overtones
what is a complex tone
collection of sine waves added together
-has harmonics
-has overtones
what is the fundamental frequency
determines the pitch (bass tone)
who is the found all this out?
Fourier
Harmonic
determined by fundamental frequency
if ff = 100, harmonics = 200, 300, 400
if ff= 50, harmonics = 100, 150, 200, 250
What is Timbre?
“tone quality”
a piano and a violin playing the same note sound different.
DIFFERENT AMPLITUDE OF HARMONIC UNDERTONES
Outer ear
1 Pinna- exposed part of the ear
2 Cannal - cannal
3 Tympanic membrane - ear drum
Middle ear
1 Ossicles
->malleus
->incus
->stapes
2 Semicircular cannels - fluids
inner ear
Cochlea - sends signals to the brain
Auditory nerve - carries the signal
Eustachian tube - pressure equalizer
Basilar membrane: the ____ base is tuned for ____ frequencies
thick; higher
Basilar membrane: the ____ apex is tuned for ____ frequencies
thin; lower
what is the organ of corti
sensory organ for hearing; located in the cochlea on the basilar membrane; has hair cells
describe the inner and outer hairs of the organ of corti
outer:
3 layers
sensitive
connects to II nerve fibers
inner:
1 layer
converting sound into signal
connects to I nerve fibers
THE AUDITTORY NERVE IS MADE UP OF II and I fibers
Tectorial membrane
sits on top of the basilar membane.
when the basilar membrane moves, the hairs rub on the Tectorial membrane to create stimulus
place code vs Temporal code (phase locking)
place code: relies on location of the vibration on the basilar membrane. can be more useful for higher frequencies
Temporal code (phase locking): relies on the timing of the hair going back and forth to measure the frequency
for sound stimulus where sound is very quite, when some hairs dont pick up on it, others _____
will / pick up the slack
Where do sound signals end up in the brain?
Temporal lobe: Primary Auditory Complex (A1)
contains pitch cells
Pitch cells
in the Auditory complex (A1)
they recognize pitches even if the fundamental tone is missing
Hearing: Conductive vs. Sensorineural
conductive - issues with outer and middle ear
sensorineural - issues with inner ear
—-> can get a cochlear implant
What does a cochlear implant do?
acts similarly to the role of cilia in the basilar membrane, but with a significant difference in mechanism.
electrical stimulation instead of movement of hairs
hearing on the horizontal plane is called ______
Azimuth (side-side)
