sound

2.01  sound. (a) Oscillation in pressure, stress, particle displacement, particle velocity, etc., propagated in a medium with internal forces (e.g., elastic or viscous), or the superposition of such propagated oscillation. (b) Auditory sensation evoked by the oscillation described in (a).

Annotation 1          Not all sounds evoke an auditory sensation, e.g., ultrasound or infrasound. Not all auditory sensations are evoked by sound, e.g., tinnitus.

Annotation 2          The medium in which the sound exists is often indicated by an appropriate adjective, e.g., air-borne, water-borne, or structure-borne.