Estimation system of spectral envelopes and group delays for sound analysis and synthesis, and audio signal synthesis system

Abstract

For high-accuracy analysis and high-quality synthesis of voice sound (singing and speech), provided herein are a system and a method for estimating from an audio signal spectral envelopes and group delays for sound analysis and synthesis with high accuracy and high temporal resolution. An estimation system of spectral envelopes and group delays includes a fundamental frequency estimation section, an amplitude spectrum acquisition section, a group delay extraction section, a spectral envelope integration section, and a group delay integration section. The spectral envelope integration section sequentially obtains a spectral envelope for sound synthesis by averaging overlapped spectra. The group delay integration section selects from a plurality of group delays a group delay corresponding to the maximum envelope of each frequency component of the spectral envelope and integrates groups delays thus selected to sequentially obtain a group delay for sound synthesis.