Hearing: Physiology and Psychoacoustics Flashcards
helicotrema
The opening that connects the tympanic and vestibular canals at the apex of the cochlea.
loudness
The psychological aspect of sound related to perceived intensity (amplitude).
tectorial membrane
A gelatinous structure, attached on one end, that extends into the middle canal of the ear, floating above inner hair cells and touching outer hair cells.
high-spontaneous fiber
An auditory nerve fiber that has a high rate (more than 30 spikes per second) of spontaneous firing; high-spontaneous fibers increase their firing rate in response to relatively low levels of sound.
Reissner’s membrane
A thin sheath of tissue separating the vestibular and middle canals in the cochlea.
timbre
The psychological sensation by which a listener can judge that two sounds with the same loudness and pitch are dissimilar. Timbre quality is conveyed by harmonics and other high frequencies.
equal-loudness curve
A graph plotting sound pressure level (dB SPL) against the frequency for which a listener perceives constant loudness.
psychoacoustics
The study of the psychological correlates of the physical dimensions of acoustics; a branch of psychophysics.
tympanic membrane
The eardrum; a thin sheet of skin at the end of the outer ear canal. The tympanic membrane vibrates in response to sound.
tympanic canal
One of three fluid-filled passages in the cochlea. The tympanic canal extends from the round window at the base of the cochlea to the helicotrema at the apex. Also called scala tympani.
frequency
For sound, the number of times per second that a pattern of pressure change repeats. Frequency is perceived as pitch.
ototoxic
Producing adverse effects on cochlear or vestibular organs or nerves.
outer ear
The external sound-gathering portion of the ear, consisting of the pinna and the ear canal.
otitis media
Inflammation of the middle ear, commonly in children as a result of infection.
phase locking
Firing of a single neuron at one distinct point in the period (cycle) of a sound wave at a given frequency. (The neuron need not fire on every cycle, but each firing will occur at the same point in the cycle.)
sine wave or pure tone
A waveform for which variation as a function of time is a sine function.
stapes
One of the three ossicles. Connected to the incus on one end, the stapes presses against the oval window of the cochlea on the other end.
characteristic frequency (CF)
The frequency to which a particular auditory nerve fiber is most sensitive.
white noise
Noise consisting of all audible frequencies in equal amounts. White noise in hearing is analogous to white light in vision, for which all wavelengths are present.
stapedius
The muscle attached to the stapes; tensing the stapedius decreases vibration.
tonotopic organization
An arrangement in which neurons that respond to different frequencies are organized anatomically in order of frequency.
incus
The middle of the three ossicles, connecting the malleus and the stapes.
stereocilium
Any of the hairlike extensions on the tips of hair cells in the cochlea that, when flexed, initiate the release of neurotransmitters.
afferent fiber
A neuron that carries sensory information to the central nervous system.
vestibular canal
One of three fluid-filled passages in the cochlea. The vestibular canal extends from the oval window at the base of the cochlea to the helicotrema at the apex. Also called scala vestibuli.
acoustic reflex
A reflex that protects the ear from intense sounds, via contraction of the stapedius and tensor tympani muscles.
efferent fiber
A neuron that carries information from the central nervous system to the periphery.
oval window
The flexible opening to the cochlea through which the stapes transmits vibration to the fluid inside.
basilar membrane
A plate of fibers that forms the base of the cochlear partition and separates the middle and tympanic canals in the cochlea.
rate-intensity function
A graph plotting the firing rate of an auditory nerve fiber in response to a sound of constant frequency at increasing intensities.