Hearing Flashcards
measure of sound intensity
Decibels
loudness
measure frequency (perceived as pitch)
Herz
cycles per second
Transduced
conversion of 1 form of energy to another
external part of the ear
pinna
ear canal
external ear
tube leading from pinna to tympanic membrane through sound waves are funneled
Tympanic Membrane
middle ear
tout membrane at inner end of ear canal
captures sound vibrations in air w some frequency as sound
ossicles
incus, malleus, stapes
transmit vibration across the middle ear
tympanic membrane to oval window
Oval window
middle ear
location on cochlea where vibrations are transmitted from ossicles to interior of cochlea
receives vibrations from tympanic membrane through ossicles
Cochlea
inner ear
snail shaped structure
contains primary receptor cells for hearing
3 parallel canals
scala vestibuli / vestibular canal (length of cochlea)
scala media / middle canal (btw vestibular and tympanic canal)
scala tympani / tympanic canal (length of cochlea)
organ of corti
cochlea of scala media
contains hair cells and terminations of auditory nerve
converts vibration from sound into neural activity
hair cells
auditory sensory cells
bridge btw basilar membrane & tectorial membrane
basilar membrane
in cochlea
contains principal structures involved in auditory transduction
Tectorial Membrane
gelatinous membrane located atop the organ corti
Sterocillia
bristle that protrudes from a hair cell in auditory or vestibular system
mechanical bridge btw basilar membrane and tectorial membrane
Cochlear Nuclei
brainstem nuclei that receive input from auditory hair cells
send output to superior olivary nuclei
superior olivary nuclei
receive input from R & L cochlea nuclei,
provide 1st binaural analysis of auditory info
tonotopic organization
organization of auditory neurons according to an orderly map of stimulus frequency from low to high
Place coding theory
pitch of sound determined by location of activated hair cells along length of basilar membrane
good for higher frequencies
Temporal Coding Theory
pitch of sound determined by rate of firing auditory neurons
good for low frequency
infrasound
less than 20 Hz
very low frequency
ultrasound
more than 20,000 hz
high frequency sound
Interaural Intensity Differences
Perceived difference in loudness between two ears
localize sound source
Intramural Temporal Differences
Difference between two ears in time arrival of sound
ear closer hears sound better
Spectral Filtering
hills and valleys of eternal ear alter amplitude of some frequencies in a sound
vertical localization of sound
Hearing loss
decreased sensitivity to sound
deafness
hearing loss so profound that speech perception is lost
conduction deafness
ossicles of middle ear fused together
vibrations of eardrum can’t be conveyed to oval window of cochlea
sensorineural deafness
caused by permanent damage / destruction of hair cells OR interruption of vestibulocochlear nerve that carries auditory info to brain
deficit in inner ear
tinnitus
sensation of noises or ringing in ears not cause by external sound
central deafness
auditory areas of brain fail to process / interpret action potentials from sound stimuli
impaired perception of complex sounds
word deafness
form of central deafness that is characterized by inability to hear words
can detect other sounds
cortical deafness
form of central deafness
damage to both sides of auditory Cortex
difficulty recognizing all complex sounds
