Movie-A-Day #99: The Conversation (1974).

It was 151 years ago that the oldest surviving recording of the human voice was made. It’s a short clip of French inventor Édouard-Leon Scott de Martinville singing “Au Clair de la Lune” into his phonautograph machine. Although Scott had built the machine a few years earlier for his studies in acoustics, this recording is the oldest one that researchers have been able to uncover. The device simply recorded sound waves as two-dimensional line tracings on paper or glass, but it laid the groundwork for the later gramophone and wax cylinder technologies.

Audio recording has gone through a long and complicated history since then. Francis Ford Coppola’s terrific thriller “The Conversation” captures one aspect of the world of sound – specifically the obsession and paranoia of audio surveillance.