Toward Improving the Performance of Epoch Extraction from Telephonic Speech

Abstract

Epoch is an abrupt closure event within a glottal cycle at which significant excitation to the vocal-tract system happens during the production of voiced speech. The state-of-the-art zero frequency filtering technique is a simple and efficient method that shows robustness in extracting the epochs from clean speech. However, this method has shown poor performance for telephonic quality speech, due to the presence of spurious zero crossings in epoch evidence, which leads to a high false alarm rate. Recently, zero-phase zero frequency resonator (ZP-ZFR) an alternative to zero frequency filter is proposed for stable implementation of zero frequency filtering technique. In this study, higher-order ZP-ZFR is investigated to improve the performance of zero frequency filtering for epoch extraction from telephonic speech. The performance of the proposed ZP-ZFR method is quantitatively evaluated on telephonic speech simulated using six standard databases having simultaneous electroglottograph recordings as ground truth. Experimental results suggest that the performance of the proposed method is significantly better than the state-of-the-art methods in terms of identification rate and false alarm rate.