Aerophone
Aerophone , noun
[Aero- + Greek {not transcribed} 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.