Detection of Vowel Onset Points in Voiced Aspirated Sounds of Indian Languages

Vowel onset point (VOP) is defined as the instant at which onset of vowel takes place. Accurate detection of VOP is useful in many applications like syllable unit recognition, end-point detection, speaker verification etc. Manually and automatically locating VOPs accurately in case of voiced aspirated (VA) sounds is found to be difficult and ambiguous. This is due to the complex nature of the speech signal waveform around the VOP. This work addresses this issue and a manual marking approach using electroglottograph (EGG) signal is described which accurately marks the VOPs without any ambiguity. The knowledge derived from this manual analysis is transformed into an automatic method for the detection of VOPs in VA sounds. An automatic method is proposed using both source and vocal tract information. VOP detection accuracy of the proposed method is found to be significantly higher than some of the state of the art techniques.