thermophone

English

Etymology

thermo- +‎ -phone

Noun

thermophone (plural thermophones)

1. A form of transducer that generates sound waves of precise power.
2. (historical) A portable telethermometer, using a telephone in connection with a differential thermometer.
3. (historical) A telephone involving heat effects, as changes in temperature (hence in length) due to pulsations of the line current in a fine wire connected with the receiver diaphragm.

Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.
(See the entry for “thermophone”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.)