Audition

amplitude

The difference between the highest and lowest point of the cycle of a sound wave, measured in decibels (dB)

frequency

The speed of fluctuations of a sound wave, measured in Hertz (Hz), which correspond to the number of cycles per second

timbre

The sensation by which people identify the difference between two sounds with the same loudness and pitch— allows us to determine the source of a sound

auditory canal

Tube-like structure that directs sounds waves to the tympanic membrane

tympanic membrane

Thin membrane which vibrates at the same frequency as sound waves entering the ear and transmits these vibrations to the ossicles

ossicles

Three small bones in the middle ear that amplify vibrations and transmit them to the inner ear

oval window

Membrane-covered opening, connects middle ear to the cochlea and relays vibrations from the ossicles

cochlea

Spiral-shaped structure filled with fluid; converts vibrations into neural signals

basilar membrane

Structure within the cochlea which vibrates in response to sounds and supports hair cells in frequency discrimination

organ of Corti

Structure on the basilar membrane composed of hair cells, supporting cells, and fibers of the cochlea

hair cells

Cells in the cochlea responsible for transduction of vibrations of the tectorial membrane into action potentials

interaural level difference (ILD)

Method of localizing sound in space using the angle of the sound, which causes differences in volume between the ears

interaural time difference (ITD)

Method of localizing sound in space using the difference in the time at which a sound arrives in one ear compared to the other

spectral composition

The balance of high and low frequencies of a sound

degree of reverberation

The number of reverberations from a sound. Sound waves bounce off surfaces, so sounds further away cause more reverberations

phoneme

Units of sound that distinguish one word from another in a particular language

respiration

The process by which the diaphragm pushes air out of the lungs, through the trachea, and up to the larynx

phonation

When the vocal folds vibrate as air pushes out of the lungs

articulation

The act of producing speech sounds using the vocal tract

coarticulation

When experienced talkers position the tongue in anticipation of the following consonant or vowel, changing the sound of the previous

categorical perception

When a stimulus changes continuously but we perceive it as belonging to discrete categories

motor theory

Theory of speech perception arguing that motor processes used to produce speech are used in reverse to understand the acoustic speech signal

tone height

Sound quality corresponding to the level of pitch and related to frequency

tone chroma

Sound quality shared by tones with the same octave interval (C3 vs. C4)

consonance

When a combination of notes sounds pleasant, because they have a simple ratio between them

dissonance

When a combination of notes sounds unpleasant, because they have a complex ratio between them

scale

A particular subset of the notes in an octave

temporal resolution

The ability to detect rapid changes in sound intensity over time

spectral resolution

The ability to distinguish between different frequencies (pitch)

congenital amusia

An unconscious deficit in perceiving music including inability to sing in tune, difficulty recognizing even popular melodies, etc.

10 microseconds

Smallest interaural time difference which can be detected by the auditory system