DICT.TW Dictionary Taiwan

 A·cous·tic a.  Pertaining to the sense of hearing, the organs of hearing, or the science of sounds; auditory.
 Acoustic duct, the auditory duct, or external passage of the ear.
 Acoustic telegraph, a telegraph making audible signals; a telephone.
 Acoustic vessels, brazen tubes or vessels, shaped like a bell, used in ancient theaters to propel the voices of the actors, so as to render them audible to a great distance.