D defs.my
Entry 2 senses Webster, 1913

Thermophone

· Ther·mo·phone · IPA
01 n. A portable form of telethermometer, using a telephone in connection with a differential thermometer.
  1. 1.
    A portable form of telethermometer, using a telephone in connection with a differential thermometer.
  2. 2.
    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.