A reflexive contraction of two tiny muscles in the middle ear in response to high-intensity sounds; it dampens the movements of the ossicles, which helps protect the auditory system from damage due to loud noises.
The difference between the maximum and minimum sound pressure in a sound wave; the physical dimension of sound that is related to the perceptual dimension of loudness.
A curve showing the minimum amplitude at which sounds can be detected at each frequency.
A graphical depiction of auditory sensitivity to specific frequencies, compared to the sensitivity of a standard listener; used to characterize possible hearing loss.
An instrument that presents pure tones with known frequency and amplitude to the right or left ear; used in estimating the listenerÌs absolute threshold for specific frequencies and to construct an audiogram.
A narrow channel that funnels sound waves gathered by the pinna onto the tympanic membrane and that amplifies certain frequencies in those waves.
The nerve that conveys signals from the hair cells in the organ of Corti to the brain; made up of Type I and Type II auditory nerve fibers bundled together.
A tapered membrane suspended between the walls of the cochlea; thicker, narrower, and stiffer at the base than at the apex.
The frequency to which each location on the basilar membrane responds most readily.
A coiled, tapered tube within the temporal bone of the head, partitioned along its length into three chambers; contains the structures involved in auditory transduction.
One of the three chambers in the cochlea; separated from the tympanic canal by the basilar membrane; contains the organ of Corti; filled with endolymph.
Hearing impairments characterized by a loss of sound conduction to the cochlea, as a result of problems in the outer or middle ear.
conductive hearing impairments
In a sound wave, a repeating segment of air pressure changes.
A physical unit used to measure sound amplitude; logarithmically related to sound pressure measured in micropascals.
The range of amplitudes that can be heard and discriminated; when applied to an individual auditory nerve fiber, the range of amplitudes over which the firing rate of the fiber changes.
A curve showing the amplitude of tones at different frequencies that sound about equally loud.
equal loudness contour
A tube connecting the middle ear and the top part of the throat; normally closed but can be briefly opened (e.g., by swallowing or yawning) to equalize the air pressure in the middle ear with the air pressure outside.
A mathematical procedure for decomposing a complex waveform into a collection of sine waves with various frequencies and amplitudes.
A depiction of the amplitudes at all frequencies that make up a complex waveform.
The physical dimension of sound that is related to the perceptual dimension of pitch; expressed in hertz, the number of cycles per second of a periodic sound wave.
The frequency of the lowest-frequency component of a complex waveform; determines the perceived pitch of the sound.
A component frequency of a complex waveform that is an integer multiple of the fundamental frequency; the first harmonic is the fundamental frequency; the second harmonic is twice the fundamental frequency, and so on.
A decrease in a personÌs ability to detect or discriminate sounds, compared to the ability of a healthy young adult.
An opening in the partitioning membranes at the apex of the cochlea; provides an open pathway for the perilymph to carry vibrations through the cochlea.
The number of cycles per second of a sound wave; the physical unit used to measure frequency.
A small bone in the inner ear; one of the ossicles; transmits sound energy from the malleus to the stapes.
incus (or anvil)
Neurons in the organ of Corti; responsible for auditory transduction.
inner hair cells
The perceptual dimension of sound that is related to the physical dimension of amplitude; how intense or quiet a sound seems.
A small bone in the inner ear; one of the ossicles; transmits sound energy from the tympanic membrane to the incus.
malleus (or hammer)
A response by outer hair cells that magnifies the movements of the basilar membrane, amplifying sounds and sharpening the response to particular frequencies.
A structure in the cochlea situated on the basilar membrane; consists of three critical componentsÛinner hair cells, outer hair cells, and the tectorial membrane.
organ of Corti
Three small bones (the malleus, incus, and stapes) in the middle ear that transmit sound energy from the tympanic membrane to the inner ear.
Neurons in the organ of Corti; serve to amplify and sharpen the responses of inner hair cells.
outer hair cells
A membrane-covered opening at the base of the cochlea; vibrations of the membrane transmit sound energy from the ossicles into the cochlea.
Waves in which the cycles of compression and rarefaction repeat in a regular, or periodic, fashion.
periodic sound waves
The outermost portion of the ear.
The perceptual dimension of sound that corresponds to the physical dimension of frequency; the perceived highness or lowness of a sound.
Frequency representation based on the displacement of the basilar membrane at different locations.
A sound wave in which air pressure changes over time according to a mathematical formula called a sine wave, or sinusoid.
A membrane-covered opening at the base of the tympanic canal in the cochlea; serves as a kind of Ïrelief valveÓ for the pressure waves traveling through the perilymph.
Hearing impairments caused by damage to the cochlea, the auditory nerve, or the auditory areas or pathways of the brain
sensorineural hearing impairments
Waves of pressure changes in air caused by the vibrations of a source.
A small bone in the inner ear; one of the ossicles; transmits sound energy from the incus to the oval window.
stapes (or stirrup)
Small hairlike projections on the tops of inner and outer hair cells.
A membrane that lies above the hair cells in the organ of Corti.
Frequency representation based on a match between the frequencies in incoming sound waves and the firing rates of auditory nerve fibers.
The difference in sound quality between two sounds with the same pitch and loudness; for complex periodic sounds, timbre is mainly due to differences in the relative amplitudes of the soundsÌ overtones; the perceptual dimension of sound that is related to the physical dimension of waveform.
A persistent perception of sound, such as a ringing or buzzing, not caused by any actual sound.
Tiny fibers connecting the tips of adjacent stereocilia on hair cells; increased tension on tip links pulls open ion channels in the membranes of the stereocilia.
One of the three chambers in the cochlea; separated from the cochlear duct by the basilar membrane; filled with perilymph.
A thin, elastic diaphragm at the inner end of the auditory canal that vibrates in response to the sound waves that strike it; it forms an airtight seal between the outer ear and the middle ear.
tympanic membrane (or eardrum)
One of the three chambers in the cochlea; separated from the cochlear duct by ReissnerÌs membrane; filled with perilymph.
A profound impairment in perceiving and remembering melodies and in distinguishing one melody from another.
An impairment in speech production or comprehension (or both) caused by damage to speech centers in the brain.
Perception of different sensory stimuli as identical, up to a point at which further variation in the stimulus leads to a sharp change in the perception.
The influence of one phoneme on the acoustic properties of another, due to the articulatory movements required to produce them in sequence.
The quality exhibited by a combination of two or more notes from a scale that sounds pleasant, as if the notes ìgo together.î
Speech sounds produced by restricting the flow of air at one place or another along the path of the airflow from the vocal folds.
The quality exhibited by a combination of two or more notes from a scale that sounds unpleasant or ìoff.î
The manner in which loudness varies as a piece of music progresses.
Frequency bands with relatively high amplitude in the harmonic spectrum of a vowel sound.
An alphabet in which each symbol stands for a different speech sound; provides a distinctive way to write each phoneme in all the human languages currently in use.
International Phonetic Alphabet (IPA)
The scale that functions as the basis of a musical composition.
The part of the vocal tract that contains the vocal folds.
larynx (or voice box)
In the production of consonants, the nature of the restriction of airflow in the vocal tract.
manner of articulation
In the perception of speech sounds, when auditory and visual stimuli conflict, the auditory system tends to compromise on a perception that shares features with both the seen and the heard stimuli; if no good compromise perception is available, either the conflict is resolved in favor of the visual stimulus or there is a conflicting perceptual experience.
A sequence of musical notes arranged in a particular rhythmic pattern, which listeners perceive as a single, recognizable unit.
melody (or tune)
A sequence of notes in which the fundamental frequency of the last note is double the fundamental frequency of the first note.
The uppermost part of the throat.
For any particular sequence of phonemes, the chances that the sequence occurs at the start of a word, in the middle of a word, at the end of a word, or across the boundary between two words.
phoneme transition probabilities
The smallest units of sound that, if changed, would change the meaning of a word.
The voice onset time at which a stop consonant transitions from being mainly perceived as voiced to being mainly perceived as voiceless.
A kind of perceptual completion in which listeners seem to perceive obscured or missing speech sounds.
In the production of consonants, the point in the vocal tract at which airflow is restricted, described in terms of the anatomical structures involved in creating the restriction.
place of articulation
The time for a sound to decay effectively to zero.
reverberation time (RT)
The temporal patterning of events in a musical composition, encompassing tempo, beat, and meter.
A particular subset of the notes in an octave.
The 12 proportionally equivalent intervals between the notes in an octave.
A graph that includes the dimensions of frequency, amplitude, and time, showing how the frequencies corresponding to each vowel sound in an utterance change over time.
Two versions of the same melody, containing the same intervals but starting at different notes.
A flap of tissue that hangs off the posterior edge of the soft palate; it can close off the nasal cavity.
A pair of membranes within the larynx.
vocal folds (or vocal cords)
In the production of stop consonants, the interval between the initial burst of frequencies and the onset of voicing.
voice onset time (VOT)
In the production of consonants, specifies whether the vocal folds are vibrating or not (i.e., whether the consonant is voiced or voiceless).
Speech sounds produced with a relatively unrestricted flow of air through the pharynx and oral cavity.