Clément Ader

Clément Ader (2 April 1841 – 5 March 1925) was a French inventor and engineer born in Muret, Haute Garonn.

Ader innovated in a number of electrical and mechanical engineering fields but within the history of audio he is known primarily for improvements to Alexander Graham Bells telephone and for a patent filed in 1881 to the German imperial patenting office covering "Improvements of Telephone Equipment For Theaters". This was the worlds first patent involving two channel stereo or binaural sound. The accommodating invention to this patent was called a "théâtrophone" and was a system of telephonic transmission where listeners received a separate channel for each ear, enabling stereophonic perception of the actors on a theatrical set over long distances (roughly 2 miles).