System and method for relative enhancement of vocal utterances in an acoustically cluttered environment

The invention discloses systems and methods for enhancing the sound of vocal utterances of interest in an acoustically cluttered environment. The system generates canceling signals (sound suppression signals) for an ambient audio environment and identifies and characterizes desired vocal signals and hence a vocal stream or multiple streams of interest. Each canceling signal, or collectively, the noise canceling stream, is processed so that signals associated with the desired audio stream or streams are dynamically removed from the canceling stream. This modified noise canceling stream is combined (electronically or acoustically) with the ambient to effectuate a destructive interference of all ambient sound except for the removed audio streams, thus "enhancing" the vocal streams with respect to the unwanted ambient sound. Cepstral analysis may be used to identify a fundamental frequency associated with a voiced human utterance. Filtering derived from that analysis removes the voiced utterance from the canceling signal.