Patent ID: 7359853

Claim:
A method of encoding and decoding a voice, comprising: using voice excitation to trigger zero-crossings of the first formant at a transmitter; outputting a digital waveform therefrom; frequency dividing the resulting digital waveform by two to reduce the sampling rate and the bandwidth required for transmission; producing, by a spectrum analyzer, a short term spectrum using an input voice; weighting the short term spectrum; generating a short term spectral frame; creating a multiplexed waveform by multiplexing the voice excitation continuously with the short term spectral frame; sending the multiplexed waveform from a transmitter to a receiver; demultiplexing the multiplexed voice excitation and short term spectrum at the receiver; frequency multiplying the demultiplexed voice excitation by two at the receiver; spectrally flattening the excitation to give equal magnitude to all harmonics at a receiver; and using the spectrally flattened harmonics as excitation for a short term spectrum to reproduce an inputted voice.