METHOD FOR MODELING AMPLITUDE OF SPECTRALLY MIXED EXCITATION SIGNAL

摘要

PURPOSE: A method for modeling an amplitude of a spectrally mixed excitation signal is provided to maintain each energy of a voiced band and a voiceless band by representing a spectrum of one harmonic as a mixture of a voiced model and a voiceless model. CONSTITUTION: A voiced probability is calculated from a voice signal of an analysis stage(200). The voiced probability is compared with a reference value(202). An amplitude(A) is calculated by using a voiced model if the voiced probability is larger than a reference value(204). An amplitude(B) is calculated by using a voiceless model if the voiced probability is not larger than a reference value(206). The voiced probability and the amplitude(A) or the amplitude(B) are transmitted(208). The voiced probability of the analysis stage is compared with a reference value(210). The amplitude(A) is synthesized with a voiced sound and the amplitude(B) obtained from the amplitude(A) is synthesized with a voiceless sound if the voiced probability of the analysis stage is larger than a reference value(212). The amplitude(B) is synthesized with the voiced sound and the amplitude(A) obtained from the amplitude(B) is synthesized with the voiceless sound if the voiced probability of the analysis stage is not larger than a reference value(214). A spectrally mixed excitation signal is obtained by mixing the voiced sound with the voiceless sound.