The Source Excitation Extraction of Speech Signal Using ZZT Method

• Main Authors: An-Jan Lo, 羅安然
• Other Authors: Soo-Chang Pei
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/15643746873886857520

碩士 === 國立臺灣大學 === 電信工程學研究所 === 102 === Speech processing has been one of the major topics in the research field of signal processing. The process of speech production can be modeled as the convolution of glottal source excitation and vocal tract filter. The research in the details of speech production and the characteristic extraction can be applied in the fields such as speech synthesis and transformation. In this thesis, we discuss the zeros of the z-transform(ZZT) algorithm developed by Dr. Baris Bozkurt[1] and its application to the extraction of the excitation pulse in the source-tract model of human speech signals. After z-transform, the zeros of the speech signals can be represented on z the plane and the mixed-phase property is revealed, which would be used in source-tract separation. On the other hand, by the study of the ZZT plot, the phase information obtained from group delay spectrum could be well improved using the Chirp Group Delay. Moreover, we present the capabilities of formant tracking by ZZT, making a comparison between the performances of ZZT with other speech signal processing tools, and apply Attenuated Main Excitation(AME) for further improvement.