Acoustics
Acoustics (#; 277) , noun
[Names of sciences in -ics, as, acoustics, mathematics, etc., are usually treated as singular. See -ics.]
(Physics) The science of sounds, teaching their nature, phenomena, and laws.
Acoustics, then, or the science of sound, is a very considerable branch of physics.
The science is, by some writers, divided, into diacoustics, which explains the properties of sounds coming directly from the ear; and catacoustica, which treats of reflected sounds or echoes.