\A"["e]r*o*phone`\, n. [A["e]ro- + Gr. ? 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.