Extraction of Fundamental Frequency From Degraded Speech Using Temporal Envelopes at High SNR Frequencies

In this paper we propose a method for extracting the fundamental frequency (f(o)) from degraded speech signals using single frequency filtering (SFF) approach. The SFF of frequencyshifted speech signal gives high signal-to-noise ratio (SNR) segments at some frequencies and hence the SFF approach can be exploited for f(o) extraction using autocorrelation function of those segments. Since the f(o) is computed from the envelope of a single frequency component of the signal, the vocal tract resonances do not affect the f(o) extraction. The use of the high SNR frequency component in a given segment helps in overcoming the effects of degradations in the speech signal, without explicitly estimating the characteristics of noise. The proposed method of fo extraction is shown to give better performance for several types of real and simulated degradations, in comparison with some of the methods reported recently in the literature.