METHOD AND APPARATUS FOR GENERATING FRAME VOICING DECISIONS OF AN INCOMING SPEECH SIGNAL

A method is disclosed for generating frame voicing decisions for an incoming speech signal having periods of active voice and non-active voice for a speech encoder in a speech communication system. The method first extracts a predetermined set of parameters from the incoming speech signal for each frame and then makes a frame voicing decision of the incoming speech signal for each frame according to a set of difference measures extracted from the predetermined set of parameters. The predetermined set of extracted parameters comprises a description of the spectrum of the incoming speech signal based on line spectral frequencies ("LSF"). Additional parameters may include full band energy, low band energy and zero crossing rate. The way to make a frame voicing decision of the incoming speech signal for each frame according to the set of difference measures is by finding a union of sub-spaces with each sub-space being described by a linear function of at least a pair of parameters from the predetermined set of parameters.