Time-Frequency Coherence for Periodic-Aperiodic Decomposition of Speech Signals

Karthika Vijayan, Jitendra Kumar Dhiman, Chandra Sekhar Seelamantula

Decomposing speech signals into periodic and aperiodic components is an important task, finding applications in speech synthesis, coding, denoising, etc. In this paper, we construct a time-frequency coherence function to analyze spectro-temporal signatures of speech signals for distinguishing between deterministic and stochastic components of speech. The narrowband speech spectrogram is segmented into patches, which are represented as 2-D cosine carriers modulated in amplitude and frequency. Separation of carrier and amplitude/frequency modulations is achieved by 2-D demodulation using Riesz transform, which is the 2-D extension of Hilbert transform. The demodulated AM component reflects contributions of the vocal tract to spectrogram. The frequency modulated carrier (FM-carrier) signal exhibits properties of the excitation. The time-frequency coherence is defined with respect to FM-carrier and a coherence map is constructed, in which highly coherent regions represent nearly periodic and deterministic components of speech, whereas the incoherent regions correspond to unstructured components. The coherence map shows a clear distinction between deterministic and stochastic components in speech characterized by jitter, shimmer, lip radiation, type of excitation, etc. Binary masks prepared from the time-frequency coherence function are used for periodic-aperiodic decomposition of speech. Experimental results are presented to validate the efficiency of the proposed method.

 DOI: 10.21437/Interspeech.2017-726

Cite as: Vijayan, K., Dhiman, J.K., Seelamantula, C.S. (2017) Time-Frequency Coherence for Periodic-Aperiodic Decomposition of Speech Signals. Proc. Interspeech 2017, 329-333, DOI: 10.21437/Interspeech.2017-726.

  author={Karthika Vijayan and Jitendra Kumar Dhiman and Chandra Sekhar Seelamantula},
  title={Time-Frequency Coherence for Periodic-Aperiodic Decomposition of Speech Signals},
  booktitle={Proc. Interspeech 2017},