Thirty Years of Vocoder Research
Homer Dudley · The Journal of the Acoustical Society of America · 1964
A program of active research on the vocoder was initiated in July 1934. The first public demonstration of the vocoder was at the Harvard Tercentenary in September 1936. Since then, there have been studies of the underlying nature of speech and the recognition of speech-sound elements in transforming from the spoken to the written word or setting up other automatic voice operation. There has also been much research directed toward straightforward bandwidth compression and such compression as an aid to the attainment of other goals. The entire field of research in speech analysis and/or synthesis is reviewed, including a discussion of limitations and requirements. A demonstration tape is played from an improved 2400-bit/sec digitized vocoder.