Patent Document ID: 4618985
Application ID: 06757205

Base Claim:
1. A speech sound generating system comprising: means for simulating the frequency response of the vocal tract, said frequency response including two or more resonant peaks or formants continuously movable in frequency, said means for simulating the frequency response of the vocal tract comprising a tunable formant filter for each of said formants; means continuously responsive to operator input for simultaneously and continuously controlling the frequency locations of each of said formants by continuously tuning said tunable formant filters; means for simulating electrically the vibration of the vocal cords, with variable pitch period; additional means continuously responsive to operator input for controlling said vocal cord pitch variation; means combining said vocal cord simulation with said frequency response simulation of the vocal tract to produce a resulting waveform; and transducing means to cause the resulting waveform to be emitted as an audible sound.

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Claim 9:
9. The speech sound generating system of claim 1 wherein said means for simulating electrically the vibration of the vocal cords comprises a vocal tract simulation circuit having an amplification ratio, and wherein said means continuously responsive to operator input for controlling the location of said formants causes voltages to vary in response to said operator input, and said voltages are applied to control the amplification ratio of said vocal tract simulation circuit through multiplication or division of signal amplitudes in one or more circuit branches, thus controlling the frequency location of said resonant peaks or formants.