Amplitude – the maximum value of a periodically varying quantity.

Basilar membrane – base lining of the organ of Corti in the inner ear

Binaural beats – when 2 tones of slightly different frequencies are presented to a different ear through headphones without interacting acoustically or electronically.  The perceived beats will give the sensation of the sound circling inside the head.

Biophysics – the study of how biology and physics interact with each other

Cerebral cortex – the extensive outer layer of gray tissue of the cerebral hemispheres, largely responsible for higher nervous functions.

Cochlea– the spiral cavity of the inner ear containing the organ of Corti

Coherent – pertaining to waves with a continuous relationship among phase

Connective tissue – any tissue in the body that maintains the form of the body and its organs and provides cohesive and internal support 

Continuum – a continuous whole, no part of which can be distinguished from neighboring parts except by arbitrary division

Critical Band– the point at which the sensation of roughness accompanying 2 tones starting in unison and moving apart in pitch becomes a sensation of smoothness

Cytoskeletons– the structure of cells that help them to maintain their shape and to move about.

Dampening – to deaden

Decibel – a unit used to measure the intensity of a sound or the power level of an electrical signal

Difference frequency – the perceived frequency of the difference between 2 frequencies of sounding tones

DNA – chromosomal constituent of living cell nuclei that determine individual hereditary characteristics.

Entrainment– training

Fascia – A flat band of tissue below the skin that covers underlying tissues and separates different layers of tissue.  Fascia also encloses muscles.

Hemispheres – right and left sides of the brain

Homeostasis –  the ability to maintain a relatively stable internal state that persists despite changes in the world outside

Incus – a small anvil-shaped bone in the middle ear, transmitting vibrations between the malleus and stapes

Just tuning – In music, just intonation or pure intonation is the tuning of musical intervals as whole number ratios of frequencies. Any interval tuned in this way is called a just interval. Just intervals consist of members of a single harmonic series of a implied fundamental. Just tuning is often used by ensembles (such as for choral or orchestra works) as the players match pitch with each other “by ear.” The “equal tempered scale” was developed for keyboard instruments, such as the piano, so that they could be played equally well (or badly) in any key. It is a compromise tuning scheme.

Limit of Discrimination – the smallest perceivable difference in frequency between 2 tones played simultaneously

Malleus – a small bone in the middle ear that transmits vibrations of the eardrum to the incus.

Matrix – a surrounding substance within which something originates, develops, or is contained

Monaural – of or involving only 1 ear, another term for monophonic- using only one channel of transmission in comparison with 2 channels as in stereophonic

Nervous System – a coordinating mechanism in all multi-cellular animals that regulates internal body functions and responses to external stimuli.  In vertebrates it consists of the brain, spinal cord, nerves, ganglia, and parts of receptor and effector organs (organs that send or receive specific stimuli.)

Nucleus – a complex, usually spherical, protoplasmic body within a living cell that contains the cell’s hereditary material and that controls its metabolism, growth, and reproduction.

Occipital region – point at which the neck connects with the back of the head

Organ of Corti – a structure in the cochlea of the inner ear which produces nerve impulses in response to sound vibrations

Parameters – a fixed limit or boundary

Phonons– an individual unit of acoustic energy used especially in mathematical models to calculate thermal and vibrational properties of solids.

Psycho-acoustics – the study of how sound and music effects the human nervous system.

Pinna – the external part of the ear in humans and other mammals

RAS (Reticular formation) – an extensive network of nerve pathways in the brainstem connecting the spinal cord, cerebrum, and cerebellum and controlling the overall level of consciousness

Stapes – small stirrup-shaped bone in the middle ear, transmitting vibrations from the incus to the inner ear. Also called ‘stirrup’.

Stereo – sound that is directed through two or more speakers so that it seems to surround the listener and to come from more than one source

Tectorial membrane – sheet-like lining covering the organ of Corti in the inner ear