1958 年 14 巻 2 号 p. 138-142
A new method of narrow band speech transmission discussed here is very similar to the so-called VOBANC of Bell Telephone Laboratories and was devised by the author in 1955. It depends on the principle of dividing each formant frequency into an exact integral ratio at the sending end and of multiplying them to recover completely the original frequencies at the receiving end. Particular type of variable filters for synthesizer was also proposed. Some difficulties in realizing the actual communication system were discussed and some ideas of improvement were given. Finally, we wish to propose a system called "PARVOC", or partial voice compressor.