An Etymological Dictionary of Astronomy and Astrophysics

A type of → longitudinal wave that consists of mechanical → vibrations of small
→ amplitude propagated in an → elastic medium. Acoustic waves exhibit phenomena like → diffraction, → reflection, and → interference, but not → polarization. Also called → sonic and → sound waves. See also
→ acoustic wave equation. The branch of physics concerned with the properties of sonic waves is called → acoustics.

See also: → acoustic; → wave.