A unique narrow band voice modulation system

A new and unique voice modulation system that utilizes the natural time division and frequency division multiplexed characteristics of voiced and unvoiced sounds in human speech has been developed theoretically and proven experimentally in the laboratory. This system, NBVM (Narrow Band Voice Modulation), allows human speech to be transmitted within a 1500 Hz bandwidth and then on reception demodulated or expanded to a full bandwidth of 3000 Hz. The reduction in bandwidth is an advantage whenever the transmission bandwidth is limited. It may also potentially be used to allow more than one speech signal to be communicated over the same channel where previously only one was possible. The speech quality is nearly comparable to telephone speech and is significantly better than current LPC and vocoder techniques. (A demonstration tape will be played). A possible hard-ware implementation and potential applications for this new technique to alleviate spectral crowding for Amateur and CB users are discussed.