Abstract: A system and method for processing of audio and speech signals is disclosed, which provide compatibility over a range of communication devices operating at different sampling frequencies and/or bit rates. The analyzer of the system divides the input signal in different portions, at least one of which carries information sufficient to provide intelligible reconstruction of the input signal. The analyzer also encodes separate information about other portions of the signal in an embedded manner, so that a smooth transition can be achieved from low bit-rate to high bit-rate applications. Accordingly, communication devices operating at different sampling rates and/or bit-rates can extract corresponding information from the output bit stream of the analyzer. In the present invention embedded information generally relates to separate parameters of the input signal, or to additional resolution in the transmission of original signal parameters.

Abstract: 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.