Improvements in the Vocoder
R. L. Milner · The Journal of the Acoustical Society of America · 1953
A number of improvements in reliability and quality have been made in the vocoder over the past several years which have not been reported in the literature. These include several basic changes in the pitch control channel which give greater reliability for different talkers as well as allow operation over greater volume ranges. Changes have also been made to optimize the quality as a function of the required band width for transmission. In particular, the band pass filter system has been proportioned to follow the Koenig aural scale (similar to mel). Demonstrations are included to illustrate the operation of the vocoder for several different talkers as well as its action when applied to individual musical instruments.