Chapter 9: Hearing: Physiology and Psychoacoustics Flashcards
amplitude or intensity
The magnitude of displacement (increase or decrease) of a sound pressure wave. Amplitude is perceived as loudness.
frequency
For sound, the number of times per second that a pattern of pressure change repeats. Frequency is perceived as pitch.
hertz (Hz)
A unit of measure for frequency. One hertz equals one cycle per second.
loudness
The physiological aspect of sound related to perceived intensity (amplitude).
pitch
The psychological aspect of sound related mainly to perceived frequency.
decibel (dB)
A unit of measure for the physical intensity of sound. Decibels define the difference between two sound as the ratio between two sound pressures. Each 10:1 sound pressure ratio equals 20 dB, and a 100:1 ratio equals 40 dB.
sine wave or pure tone
A waveform for which variation as a function of time is a sine function.
Spectrum
A representation of the relative energy (intensity) present at each frequency.
harmonic spectrum
The spectrum of a complex sound in which energy is at integer multiples of the fundamental frequency.
fundamental frequency
The lowest frequency component of a complex periodic sound.
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.
pinna
The outer, funnel like part of ear.
ear canal
The canal that conducts sound vibrations from the pinna to the tympanic membrane and prevents damage tot he tympanic membrane.
Tympanic membrane (eardrum)
The eardrum; a thin shit of skin at the end of the outer ear canal. The tympanic membrane vibrates in responds to sound.
outer ear
The external sound-gathering portion of the ear, consisting of the pinna and the ear canal.
middle
An air-filled chamber containing the middle bones, or ossicles. The middle ear conveys and amplifies vibration from the tympanic membrane to the oval window.
ossicle
Any of three tiny bones of the middle ear: malleus, incus, and stapes.
malleus
One of the three ossicles, receives vibration from the tympanic membrane and is attached to the incus.
incus
The middle of the three ossicles connecting malleus to stapes.
Stapes
Third ossicle. Connects to incus and presses against oval window of cochlea.
oval window
The flexible opening to the cochlea through which the stapes transmits vibration to the fluid inside.
inner ear
A hollow cavity in the temporal bone of the skull, and the structures within the cavity: the cochlea and the semicircular canals of the vestibular system.
tensor tympani
The muscle attached to the malleus; tensing the tensor tympani decreases vibration.
stapedius
The muscle attached to the stapes. Tensing the steapedius decreasese vibration,
acoustic reflex
A reflex that protects the ear from intense sounds, via contraction of the stapedius and tensor tympani muscles.
cochlea
A spiral structure of the inner ear containing the organ or Corti.
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.
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.
middlew canal
One of three fluid filled passages in the cochlea. The middle canal is in between vestibular/tympanic canals at apex of cochlea.
helicotrema
The opening that connects the tympanic and vestibular canals at the apex of the cochlea