detectograph

English

Etymology

From detect +‎ -o- +‎ -graph. Possibly originally a trademark.

Noun

detectograph (plural detectographs)

1. An early audio recording device used in wiretaps.
   • 1914, United States Congress, Congressional edition:

     There were no stenographers and no detectographs in those days, and there is no record of this interview, fraught with such tremendous benefit to Germany and all Europe […]

   • 1915, Journal of the Engineers' Society of Pennsylvania, volume 7:

     […] it is taken for granted that the discussions are not significant, otherwise we might consider the advisability of capturing these golden words by the installation of detectographs throughout the club house.