Section 3 Auditory System Flashcards
Sound can be categorized according to:
freq and amp
Vibration, per second, freq determines:
pitch
Typical speech is __ Hz:
500-3000Hz
Amplitude is measured in:
decibels
Loudness is measured in:
vibrations per second
How many decibels is normal conversation, whisper, and lawnmower?
60dB, 15dB, and 90dB
0 dB is:
near silence
Where is the auditory system most sensitive?
1-4 kHz
Above what dB do you no longer hear tone, but it turns to pain or noise?
120dB
What is the perception limit of humans?
about 4 kHz (this is at about 100dB)
The far L side of the Freq vs dB graphs starts at how many dB?
- This is the dB level around which the lowest frequencies can be heard
How many decibels are we at when the perception limit has been reached?
about 100 dB
T or F? The eardrum is located in the middle ear.
F. outer ear.
Parts of the outer ear:
pinna, external auditory meatus/canal, and ear drum
ear drum is aka:
typmpanum
What structure is physically connected to the eardrum?
Maleus
Parts of the middle ear:
malleus, incus, stapes (hammer, anvil, stirrup)
How many tiems do the ossicles amplify the amplitude of sound?
25 times the amplitude
T or F? The moves of the tympanum are very large.
F.
Human ear can detect sounds that involve air moves of less than:
1nm
Most efficient frequency range:
1-4kHz
Interruption or calcification of the ossicle chain can result in a hearing loss of:
60dB
What muscles protect the cochlea from damage due to very loud noise?
Stapedius and tensor tympani
When does the stapediius contract?
Just before we speak or chew, in response to loud external sound
Damage to what can cause an intolerance to noise and difficulty hearing in noisy surroundings?
stapedius m.
The tensor tympani m. acts:
reflexively with stapedius
To what is the tensor tympani attached?
malleus and tympanic membrane (pulls inward to make more tense)
What takes place in the cochlea?
Sound energy is transduced into neural signals
How is the cochlea divided?
Into 3 sub-tubes separated by 2 membranes
The basilar membrane separates:
endolymph from perilymph
What does the basilar membrane contain?
The cochlear hair cells
Hair cells project into:
endolymph
Info is transferred from the cochlea to the brain via this ganglion:
spiral ganglion
All neural action takes place here:
basilar membrane
Hair cell bundles are always associated with:
endolymph
What causes vibration of the basilar membrane?
Movements of cochealr fluids in response to head moves
Most medial portion of the inner ear:
helicotrema
What region of the basilar membrane vibrates the most in response to high frequencies?
base
What region of the basilar membrane vibrate the most in response to low frequencies?
apex
The basilar membrane gets narrower and stiffer going toward this end:
base
What allows for the different parts of the basilar membrane to respond differentially to different parts of sound?
variability in width and stiffness
Are higher or lower Hz frequencies hear in the center of the coiled cochlea?
lower
Parts of the organ of corti:
tectorial membrane and hair cells