| Popis: |
For voiced speech, significant excitation of the vocal tract system is due to sequence of impulse-like events in the vocal fold vibration. Significant excitations take place around the instants of glottal closure (GCIs), which are often referred as epochs. In literature, most of the epoch extraction algorithms rely on estimation of the excitation source, by attempting to remove the vocal tract system characteristics. Performance of these algorithms depends on the effectiveness of excitation source estimation methods. Algorithms such as zero frequency filtering (ZFF) and speech event detection using the residual excitation and a mean-based signal (SEDREAMS) detect epochs from the smoothened speech signal by exploiting temporal cues. But these algorithms rely on the value of pitch period. The objective of this paper is to develop an algorithm which does not require any apriori information of pitch period, and can be implemented in real-time applications. This algorithm exploits the harmonic property of sequence of impulse-like excitations to obtain the local pitch period, and temporal cues in the filtered signal to obtain epoch locations. |
