Separation of Mixed Audio Signals by Decomposing Hilbert Spectrum with Modified EMD

Md. Khademul Islam MOLLA  Keikichi HIROSE  Nobuaki MINEMATSU  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E89-A   No.3   pp.727-734
Publication Date: 2006/03/01
Online ISSN: 1745-1337
DOI: 10.1093/ietfec/e89-a.3.727
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Multidimensional Signal Processing and Its Application)
Category: Speech/Audio Processing
Keyword: 
audio source indexing,  audio source separation,  empirical mode decomposition (EMD),  Hilbert spectrum,  

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Summary: 
The Hilbert transformation together with empirical mode decomposition (EMD) produces Hilbert spectrum (HS) which is a fine-resolution time-frequency representation of any nonlinear and non-stationary signal. The EMD decomposes the mixture signal into some oscillatory components each one is called intrinsic mode function (IMF). Some modification of the conventional EMD is proposed here. The instantaneous frequency of every real valued IMF component is computed with Hilbert transformation. The HS is constructed by arranging the instantaneous frequency spectra of IMF components. The HS of the mixture signal is decomposed into subspaces corresponding to the component sources. The decomposition is performed by applying independent component analysis (ICA) and Kulback-Leibler divergence based K-means clustering on the selected number of bases derived from HS of the mixture. The time domain source signals are assembled by applying some post processing on the subspaces. We have produced experimental results using the proposed separation technique.