Chapter 9: Hearing; physiology and psychoacoustics Flashcards
amplitude/intensity
the magnitude of displacement of a sound pressure wave. Perceived as loudness.
frequency
the number of times per second that a pattern of pressure changes repeats. Perceived as pitch.
hertz (Hz)
A nut of measure for recency. 1 Hz = 1 cycle/second
loudness
psychological aspect of sound related to intensity (amplitude)
pitch
psychological aspect of sound related to frequency.
decibel (dB)
A unit of measure for the physical intensity of sound. Defined as differences between 2 sounds as ratios; each 10:1 sound pressure ration = 20 dB and 100:1 = 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
fundamental frequency
the lowest frequency component of a complex periodic sound
timbre
psychological sensation which a listener can judge that 2 sounds with the same loudness and pitch are different. Timbre quality is conveyed by harmonics and other high frequencies.
pinna
outer, funnel-like part of the ear
ear canal
the canal that conducts sounds vibration from the pinna to the tympanic membrane and prevents damage to the membrane.
tympanic membrane
ear drum, vibrates in respond to sound.
outer ear
external sound-gathering portion of ear. Pinna + ear canal
middle ear
air-filled chamber containing the middle bones (ossicle). Middle ear conveys and amplifies vibration from the tympanic membrane to the oval window.
ossicle
3 bones = malleus, incus, and stapes.
malleus
receives vibration from tympanic membrane sends to incus
incus
between malleus and stapes
stapes
between incus and oval window of the cochlea
oval window
receives vibration signals from stapes, fluid-filled chamber
inner ear
A hollow cavity in the temporal bone of the skull, and strutters within this cavity: the cochlea and the semicircular canal of the vestibular system
tensor tympani
muscles attached to the malleus; tensing the tensor tympani decreases vibration.
stapedius
muscles attached to the stapes; tensing the stapedius decreases vibration
acoustic reflex
reflex that protects the ear from intense sounds, via contraction of the stapedius and tensor tympani muscles
tympanic canal
1 of the 3 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 3 fluid-filled passages in the cochlea. The vestibular canal extends from the oval window at the base of the cochlea to the hemicotrema at the apex. (scala vestibuli)
middle canal
1 of the 3 fluid-filled passages in the cochlea. The middle canal is sandwiched between the tympanic and vestibular canals and contains the cochlear partition. (scala media)
helicotrema
the opening that connects the tympanic and vestibular canal at the apex of the cochlea