Vehicle speech synthesis system equipment - mixes partial signal elements amplitude modulated at formant and noise frequencies

摘要

The speech synthesis system for use with compact equipment in a vehicle in which part signals corresponding to the speech level are added, uses a frequency which is a whole number times the basic speech frequency. A first set of part signals is used whose frequencies are near the formant frequency spectrum and each is amplitude modulated. Side lines are formed whose opposed frequency spacing is the same as the basic speech frequency. Three of the first three formants have a speech level corresponding to the first part signals, which are amplitude modulated according to a sawtooth function. The basic oscillation frequency of the sawtooth function is the same as the basic speech frequency. A second set of part signals having a frequency which approximates to the average frequency of a noise frequency are amplitude modulated with a noise signal. These modulated signals is mixed with an inverted signal of the same frequency and nearly the same amplitude.