Patent ID: 6909924

Claim:
A method for shifting a pitch, comprising the steps of: storing acoustic signals, which are expressed by a series of digital signals, in a memory; reading a first series of signals at a fade-in side and a second series of signals at a fade-out side from said memory; performing at least one of compacting and expanding a time axis of at least one of said first and second series of signals; wherein the step of performing includes performing a primary phase difference adjustment, and performing a secondary phase adjustment having an adjustment level that is finer than the primary phase adjustment; cross-fading said first and second series of signals after the step of performing to produce an output signal; detecting and compensating for a phase difference between said first and second series of signals by adjusting blocks of said first and second series of signals to minimize said phase difference; and the step of detecting and compensating using fundamental tones in said first and second series of signals.