- Hugh Davies
An electronic device for analysing and resynthesizing sounds. The original Vocoder (‘voice coder’) was developed by Homer Dudley in 1936 at the Bell Telephone Laboratories in Murray Hill, New Jersey, for telephonic applications; it has also proved a valuable tool in speech research and has found applications in electroacoustic music. Speech, music or other sound is analysed by a set of filters, each covering a different band of frequencies, that subdivide the entire audio spectrum; the fundamental frequency of the input is used as the ‘programme’ in a Modulation process to control the frequency of an audio oscillator (which supplies ‘buzz’) and a noise generator (‘hiss’). The resulting signal is then passed through a second set of filters, each of which is ‘tuned’ by the amount of electrical information received by their counterparts in the first set, recreating the original signal electronically. A telephone line may intervene between the analysis and synthesis sections....