[3] BAHOURA M, ROUAT J. Wavelet speech enhancement based on the Teager energy operator[J]. IEEE Signal Processing Letters, 2001, 8(1):10-12.
[4] FAROOQ O, DATTA S. Mel filter-like admissible wavelet packet structure for speech recognition[J]. IEEE Signal Processing Letters, 2001, 8(7):196-198.
[7] MA X, ZABARAS N. Kernel principal component analysis for stochastic input model generation[J]. Computational Physics, 2010, 230(19):7311-7331.