n. [ Aëro- + Gr. &unr_; voice. ] (a) A form of combined speaking and ear trumpet. (b) An instrument, proposed by Edison, for greatly intensifying speech. It consists of a phonograph diaphragm so arranged that its action opens and closes valves, producing synchronous air blasts sufficient to operate a larger diaphragm with greater amplitude of vibration. [ Webster 1913 Suppl. ]