Sound synthesizing apparatus

Abstract

An analog sound signal the time axis of which is compressed is sampled responsive to a write clock signal and the sampled output is stored in an analog shift register having a given capacity, whereupon the stored signal is read out from the analog shift register responsive to a read clock signal the frequency of which is smaller than that of the write clock signal. The above described operation is alternately repeated, whereby the output signal read out from the analog shift register is compiled for sound synthesization. The synthesizing junction of the sound signal is controlled by a microcomputer. The microcomputer is adapted to evaluate the similarity of the data concerning the waveform at the trailing end portion of a preceding sound element stored in the random-access memory and the data concerning the waveform at the leading end portion of the succeeding sound element stored in the random-access memory. Evaluation of similarity of the waveforms is effected by evaluating a mean square error or a mutual correlation function of two sets of data. The shift amount of the leading end of the succeeding sound element to be joined to the trailing end portion of the preceding sound element is determined based upon the result of the evaluation, whereby a read circuit is controlled to correct the time axis of the succeeding sound element, thereby to achieve continuity of the waveform at the synthesizing junction of the preceding and succeeding sound elements.