In this paper, we propose a method for detection of glottal closure instants (GCI) in the voiced regions of speech signals. The method is based on periodicity of significant excitations of the vocal tract system. The key idea is the computation of coherent covariance sequence, which overcomes the effect of dynamic range of the excitation source signal, while preserving the locations of significant excitations. The Hilbert envelope of linear prediction residual is used as an estimate of the source of excitation of the vocal tract system. Performance of the proposed method is evaluated in terms of the deviation between true GCIs and hypothesized GCIs, using clean speech and degraded speech signals. The signal-to-noise ratio (SNR) of speech signals in the vicinity of GCIs has significant bearing on the performance of the proposed method. The proposed method is accurate and robust for detection of GCIs, even in the presence of degradations.
Bibliographic reference. , Guruprasad S. / , Yegnanarayana B. / , Sri Rama Murty K. (2007): "Detection of instants of glottal closure using characteristics of excitation source", In INTERSPEECH-2007, 554-557.