Soon after its invention in 1878 the Edison phonograph (above) was on sale in most western countries, producing recorded sound from a grooved wax cylinder. The top image shows the interior of a later Ericsson carbon microphone.
28 : Microphone
1877
Soon after its invention in 1878 the Edison phonograph (above) was on sale in most western countries, producing recorded sound from a grooved wax cylinder. The top image shows the interior of a later Ericsson carbon microphone.
Much emphasis is placed on bird song as a means by which we can identify different species (and, indeed, how they identify themselves), and central to our understanding of avian vocalisations is the ability to record the sounds birds make. Cue the microphone.
The first ‘mic’ was the subject of bitter argument and courtroom battle as American inventors Thomas Edison and Emile Berliner registered patents for the first such carbon prototypes in 1877. These small devices with a visual resemblance to buttons converted sound to electrical charge by using the pressure on carbon granules between two metal plates to transform sound waves to a current. Edison and Berliner would be racing neck-and-neck for much of the early history of recorded sound.
However, listening to recorded sound also necessitated a medium for its preservation. Though sound had first been represented visually by the phonautograph in 1857, Edison was able to manufacture the first phonograph in 1878, just a year after the first microphone. It consisted of a wax, foil or lead cylinder onto which a stylus engraved grooves, according to changes in air pressure created by the original sound waves. Amplification of the resulting grooves could produce a playback of the original sounds, a process that still seems slightly magical no matter to what depth it is explained.
This aura of inexplicability certainly piqued public interest and fuelled the ensuing race, and Berliner was able to trump Edison with the gramophone, using a similar technique to produce audio from grooves on a flat disc. This had the advantage of being easily reproduced commercially and cheaply, by impressing the grooves onto a negative master which then imprinted them on a plate or disc made of shellac, a resin secreted by a scale insect from India and South-East Asia. Through the first half of the 20th century, countless discs of this material were sold, including many recordings of bird song.
Edison’s phonographs went into commercial production almost immediately, and one purchased at the Leipzig Fair in Germany in 1889 was given as a present to eight-year-old Ludwig Koch, with dramatic results (see pages 70-71).