A Robust and Alternative Approach to Zero Frequency Filtering Method for Epoch Extraction

P. Gangamohan, B. Yegnanarayana


During production of voiced speech, there exists impulse-like excitations due to abrupt closure of vocal folds. These impulse-like excitations are often referred as epochs or glottal closure instants (GCIs). The zero frequency filtering (ZFF) method exploits the properties of impulse-like excitation by passing a speech signal through the resonator whose pole pair is located at 0 Hz. As the resonator is unstable, the polynomial growth/decay is observed in the filtered signal, thus requiring a trend removal operation. It is observed that the length of the window for trend removal operation is critical in speech signals where there are more fluctuations in the fundamental frequency (F0). In this paper, a simple finite impulse response (FIR) implementation is proposed. The FIR filter is designed by placing large number of zeros at (f_s)/(2)] Hz (fs represents the sampling frequency), closer to the unit circle, in the z-plane. Experimental results show that the proposed method is robust and computationally less complex when compared to the ZFF method.


 DOI: 10.21437/Interspeech.2017-1172

Cite as: Gangamohan, P., Yegnanarayana, B. (2017) A Robust and Alternative Approach to Zero Frequency Filtering Method for Epoch Extraction. Proc. Interspeech 2017, 2297-2300, DOI: 10.21437/Interspeech.2017-1172.


@inproceedings{Gangamohan2017,
  author={P. Gangamohan and B. Yegnanarayana},
  title={A Robust and Alternative Approach to Zero Frequency Filtering Method for Epoch Extraction},
  year=2017,
  booktitle={Proc. Interspeech 2017},
  pages={2297--2300},
  doi={10.21437/Interspeech.2017-1172},
  url={http://dx.doi.org/10.21437/Interspeech.2017-1172}
}