Dynamic time warping comb filter for the enhancement of speech degraded by white Gaussian noise

An attempt is made to enhance speech degraded by added noise by exploiting the periodic nature of voiced speech. A modification of the adaptive comb filter is employed for this purpose. Problems which may arise when using the periodicity of the speech for enhancement include significant distortion caused by comb filtering a time-varying waveform (called temporal smearing) as well as the variation in pitch from period to period (called overload). It is shown that the dynamic time warping (DTW) comb filter corrects for variations in the vocal tract as well as the variation in pitch by using DTW. A computationally straightforward but suboptimal implementation of the time warping algorithm is used to improve the performance of the comb filter algorithm. Performance is based on computational complexity, informal listening tests, and segmental SNR.<>