Modification of acoustic signals using sinusoidal analysis and synthesis

An analysis and synthesis system for sound is provided that can independently modify characteristics of audio signals such as pitch, duration, and timbre. High-quality pitch-scaling and time-scaling are achieved by using a technique for sinusoidal phase compensation adapted to a sinusoidal representation. Such signal modification systems can avoid the usual problems associated with interpolation-based re-sampling so that the pitch-scaling factor and the time-scaling factor can be varied independently, arbitrarily, and continuously. In the context of voice modification, the sinusoidal representation provides a means with which to separate the acoustic contributions of the vocal excitation and the vocal tract, which can enable independent timbre modification of the voice by altering only the vocal tract contributions. The system can be applied to efficiently encode the pitch in sinusoidal models by compensating for pitch quantization errors. The system can also be applied to non-speech signals such as music.