from the GNU version of the Collaborative International Dictionary of English
- n. A form of combined speaking and ear trumpet.
- n. 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.
from The Century Dictionary and Cyclopedia
- n. An apparatus invented by Edison for increasing the intensity (amplitude) of sound-waves, as those from spoken words.
- n. An instrument having the functions of both an ear-trumpet and a speaking-trumpet.
Sorry, no etymologies found.