Abstract: A karaoke type system allows a participant to sing on key with a prerecorded song. A microphone produces an input signal that corresponds to a singer's voice, and a pitch corrector samples the input vocal signal and determines its pitch. The pitch corrector reads a series of codes that are stored with the prerecorded song that indicates the pitch at which the input vocal signal is to be sung in order to be on key with the prerecorded song. The pitch corrector shifts the pitch of the input vocal signal to be on key.

Abstract: Disclosed are a method and apparatus for analyzing an input vocal signal to produce a plurality of harmony signals that are combined with the input vocal signal to produce a multivoice signal. The method makes a current estimate of the fundamental frequency of the input vocal signal and determines if the current estimate is the correct estimate of the fundamental frequency. If the current estimate is correct, a reference note is assigned to correspond to the current estimate and a plurality of harmony notes are selected to correspond to the reference note. The method then generates a plurality of harmony signals by scaling the input vocal signal with a piecewise linear approximation of a Hanning window to extract a portion of the input vocal signal and by replicating the extracted portion at a plurality of rates equal to the fundamental frequencies of each of the harmony notes. The plurality of harmony signals and the input vocal signal are combined to produce the multivoice signal.

Abstract: Disclosed are a method and apparatus for analyzing an input vocal signal to produce a plurality of harmony signals that are combined with the input vocal signal to produce a multivoice signal. The method makes a current estimate of the fundamental frequency of the input vocal signal and determines if the current estimate is the correct estimate of the fundamental frequency. If the current estimate is correct, a reference note is assigned to correspond to the current estimate and a plurality of harmony notes are selected to correspond to the reference note. The method then generates a plurality of harmony signals by scaling the input vocal signal with a piecewise linear approximation of a Hanning window to extract a portion of the input vocal signal and by replicating the extracted portion at a plurality of rates equal to the fundamental frequencies of each of the harmony notes. The plurality of harmony signals and the input vocal signal are combined to produce the multivoice signal.