Improved method for epoch extraction in high pass filtered speech

The objective of present work is to improve the epoch estimation performance in high pass filtered (HPF) speech using conventional zero frequency filtering (ZFF) approach. The strength of impulse at zero frequency is significantly attenuated in case of HPF speech and hence shows significant degradation in epoch estimation performance by ZFF approach. Since linear prediction (LP) residual of speech is characterized by sharper impulse discontinuities at epochs location compared to speech waveform, the present work uses LP residual of HPF speech for epoch estimation using ZFF method. The Gabor filtering on LP residual is carried out for further increasing strength of impulses at epochs location of LP residual. The epochs location are estimated by ZFF of Gabor filtered LP residual. The performance of proposed method is better compared to that of existing Hilbert envelope based ZFF approach with improved epoch identification accuracy.