in general, denotes any thing that relates to the ear, the sense of hearing, or the doctrine of sounds.

ACOUSTIC Duct, in Anatomy, the same with meatus auditorius, or the external passage of the ear. See ANATOMY.

ACOUSTIC Instrument, or auricular tube. See ACOUSTICS.

ACOUSTIC Vessels, in the ancient theatres, were a kind of vessels made of brass, shaped in the bell fashion, which being of all tones within the pitch of the voice or even of instruments, rendered the sound more audible, so that the actors could be heard through all parts of theatres which were even 400 feet in diameter.

ACOUSTIC Disciples, among the ancient Pythagoreans, those more commonly called ACOUSMATICI.