A decision tree procedure for voiced/Unvoiced/Mixed excitation classification of speech

Pattern classification techniques, which have been successful in determining if a segment of speech is voiced or unvoiced, are used to determine if a speech segment is voiced, unvoiced, or a combination of the two (mixed). The technique employs a binary decision procedure first to determine if the segment is predominantly voiced or unvoiced, and then to determine if the segment is produced by a mixture of the two modes of excitation. The sequence of decisions is structured as a binary tree. Also presented is a method of determining which features of the speech segment are to be used in making each of the binary decisions in the tree. In preliminary tests, classification accuracy of 95% has been obtained.