Analysis of algorithms to estimate glottal closure instants from speech signals

Abstract

Estimation of glottal closure instants (GCIs) plays a vital role in pitch-synchronous speech processing. The current work performs a qualitative and quantitative review of six existing GCI estimation algorithms, namely, group delay (GD)-based algorithm, DYPSA, YAGA, ZFF, SEDREAMS and DPI algorithm. This paper differs from existing review papers in that, a detailed analysis on the parameters affecting each algorithm is presented. The optimized set of parameters, derived from this analysis, is then used to perform a comparative analysis of the algorithms. Further, in addition to evaluating the performance of the algorithms on clean and noisy speech, performance on telephone speech is analyzed as well. The algorithms are also evaluated on pathological speech, to analyze their performance in the presence of pitch jitter. In terms of the identification rate, the DPI algorithm outperforms the other algorithms on clean speech, while SEDREAMS and ZFF are observed to be highly robust to noise. On telephone speech, however, DYPSA and GD-based algorithm exhibit superior performance. The GD algorithm also performs better than the other algorithms in the presence of pitch jitter. The algorithms are also evaluated in terms of the computation time, and ZFF is observed to be faster than the rest.