Patent ID: 7579545

Claim:
A waveform producing apparatus comprising: a storage device storing a plurality of sets of waveform data, each of the sets of waveform data including a waveform to be read out along a time axis and a plurality of cycle synchronizing points in correspondence with predetermined points along the time axis of said waveform, said waveform included in each of the sets of waveform data being a waveform varying over time, said plurality of cycle synchronizing points being indicative of periodic specific phase positions where the one set of waveform data should be synchronized in phase with another of the sets of waveform data; and a processor coupled with said storage device and adapted to: read out, along a time axis, at least two of the sets of waveform data from said storage device, wherein when waveform data of one of the at least two sets of waveform data is read out at any one of said predetermined points, corresponding one of said plurality of cycle synchronizing points is read out from said storage device, control readout of at least one of the at least two sets of waveform data on the basis of the cycle synchronizing point read out from said storage device in such a manner that respective readout locations of the at least two sets of waveform data are synchronized with each other at least at the specific phase position indicated by the cycle synchronizing point, and synthesize a tone waveform by combining the at least two sets of waveform data read out from said storage device under control of said processor.