Chapter 11 Flashcards
physical definition: pressure changes in the air or other medium.
perceptual definition: the experience we have when we hear.
sound
the pattern of air pressure changes, which travels through air at 340 meters per second (and through water at 1,500 meters per second)
sound wave
occurs when changes in air pressure occur in a pattern described by a mathematical function called a sine wave.
pure tone
the number of cycles per second that the pressure changes repeat
frequency
the size of the pressure change
amplitude
the units used to measure frequency.
Hertz (Hz)
a unit of measuring sound used by auditory researchers which converts the large range of sound pressures into a more manageable scale.
Decibel (dB)
a notation added to indicate that decibels were determined using the standard pressure p of 20 micropascals.
sound pressure level (SPL)
the term used to refer to the sound pressure of a sound stimulus in decibels
sound level
a waveform that undergoes a pattern of changes, returns to its original pattern, and then repeats the same pattern of changes.
periodic waveform
The repetition rate of a periodic waveform
fundamental frequency
complex tones that are made up of a number of pure tone (sine wave) components added together.
harmonic
a pure tone with frequency equal to the fundamental frequency. Usually called the fundamental of the tone.
first harmonic
pure tones with frequencies that are whole-number (2, 3, 4, etc.) multiples of the fundamental frequency.
higher harmonics
provides a way of indicating a complex tones fundamental frequency and harmonics that add up to the tones complex waveform.
frequency spectra
the perceptual quality most closely related to the level or amplitude of an auditory stimulus, which is expressed in decibels.
loudness
indicates the threshold for hearing versus frequency.
audibility curve
the area in which we can best hear the tones that fall there.
auditory response area
curves that indicate the sound levels that create the same perception of loudness at different frequencies.
equal loudness curves
the property of auditory sensation in terms of which sounds may be ordered on a musical scale extending from low to high.
pitch
the perceptual experience of increasing pitch that accompanies increases in a tones fundamental frequency.
tone height
the position of a note within the musical octave
tone chroma
a series of eight notes occupying the interval between (and including) two notes, one having twice or half the frequency of vibration of the other.
octave
pitch remains the same, even when the fundamental or other harmonics are removed.
effect of the missing fundamental
the quality that distinguishes between two tones that have the same loudness, pitch, and duration, but still sounds different.
timbre
the buildup of sound at the beginning of the tone.
attack
the decrease in sound at the end of the tone.
decay
the pattern of pressure changes in the waveform repeats.
periodic sounds
the pattern of pressure changes in the waveform that do not repeat.
aperiodic sounds
the area in which sound waves first pass through and consists of the pinnae and the auditory canal.
outer ear
the structures that stick out from the sides of the head.
pinnae
a tubelike recess about 3 cm long that protects the eardrum.
auditory canal
the membrane of the middle ear, which vibrates in response to sound waves.
tympanic membrane/eardrum
occurs in the auditory canal when sound waves that are reflected back from the closed end of the auditory canal interact with sound waves that are entering the canal.
resonance
the natural frequency of an object where it tends to vibrate at a higher amplitude.
resonant frequency
a small cavity, about 2 cubic centimeters in volume, that separates the outer and inner ears.
middle ear
the three smallest bones in the body.
ossicles
aka the hammer. Set into vibration by the tympanic membrane, to which it is attached.
malleus
aka the anvil. Receives the vibrations transmitted by the malleus and transmits it to the stapes.
Incus
aka the stirrup. Receives vibrations from the incus and transmits them to the inner ear.
stapes
aka the stirrup. Receives vibrations from the incus and transmits them to the inner ear.
stapes
connective tissue membrane located at the end of the middle ear and the beginning of the inner ear.
oval window
the smallest skeletal muscles in the body that are attached to the ossicles, and at very high sound levels they contract to dampen the ossicles’ vibration.
middle ear muscles
the semicircular canals and cochlea, which form the organs of balance and hearing and are embedded in the temporal bone.
inner ear
the semicircular canals and cochlea, which form the organs of balance and hearing and are embedded in the temporal bone.
inner ear
the spiral cavity of the inner ear containing the organ of Corti.
cochlea
the area of the uncoiled cochlea that separates the upper and lower half.
cochlear partition
a structure in the cochlea of the inner ear which produces nerve impulses in response to sound vibrations.
Organ of Corti
the receptors for hearing.
hair cells
a membrane in the cochlea that bears the organ of Corti.
basilar membrane
a highly hydrated extracellular matrix that resides above the hair bundles of mechanosensory hair cells in the cochlea.
tectorial membrane
a small process at the tip of a hair cell that bends in response to pressure changes.
stereocilia
extracellular filaments that stretch and open tiny ion channels in the membrane of the stereocilia, which function like trapdoors.
tip links
firing at the same place in the sound stimulus.
phase locking
the movement that scientist Bekesy described for the basilar membrane’s vibration.
traveling wave
the places on the membrane that vibrate the most
apex
area near the oval window, place on the membrane that vibrates the least
base
an illustration detailing the sorting of frequencies, with high frequencies activating the base of the cochlea and low frequencies activating the apex.
tonotopic map
determined by presenting pure tones of different frequencies and measuring the sound level necessary to cause the neuron to increase its firing above the baseline or “spontaneous” rate in the absence of sound.
frequency tuning curve
the frequency to which the neuron is most sensitive or has the lowest sound level threshold.
characteristic frequency
an inactive mechanical process that took place in the outer hair cells.
cochlear amplifier
a theory that is based on the relation between a sounds frequency and the place along the basilar membrane that it activated.
place theory
The low-order harmonics of a complex tone can be separated out by a single auditory filter
resolved harmonics
The high-order harmonics of a complex tone evoke a complex temporal pattern of activation on the basilar membrane whose envelope repeats at the fundamental period of the waveform.
unresolved harmonics
a sound stimulus created by Edward Burns and Neil Viemeister that wasn’t associated with vibration of a particular place on the basilar membrane, but which created a perception
amplitude-modulated noise
a stimulus that contains many random frequencies so it doesn’t create a vibration pattern on the basilar membrane that corresponds to a specific frequency.
noise
the level (or intensity) of the noise was changed so the loudness of the noise fluctuated rapidly up and down.
amplitude modulation
the major mechanism of pitch perception
temporal coding
structures below the cerebral cortex
subcortical structures
cochlear nucleus–> superior olivary nucleus–> inferior colliculus–> medial geniculate nucleus–> primary auditory
sequence of subcortical structures
neurons tuned to a specific pitch.
pitch neurons
occurs when loud noises cause degeneration of the hair cells.
noise-induced hearing loss
sounds heard during leisure activities (both wanted and unwanted)
leisure noise
an audiogram that reflects normal hearing sensitivity across all frequency ranges, but speech-in-noise tests reveal a deficit.
hidden hearing loss
a plot of hearing loss versus frequency
audiogram
