ISCA Archive ICSLP 2002
ISCA Archive ICSLP 2002

Sparse and independent representations of speech signals based on parametric models

Hugo L. Rufiner, Luis F. Rocha, John Goddard Close

Recently methods for obtaining sparse representations of a signal using overcomplete dictionaries of waveforms have been studied, often motivated by the way the brain seems to process certain sensory signals. Algorithms have been developed using either a specific criterion to choose the waveforms occurring in the representation from a fixed dictionary, or to construct them as part of the method. In the case of speech signals, most approaches do not take into consideration the important temporal correlations that exist; these are known to be well approximated using linear models. Incorporating this type of a priori knowledge of the signal can facilitate the search for a suitable solution and also help with the interpretation of the representation found. In the present paper a method is proposed for obtaining a sparse representation using a generative parametric model. An example, using speech signals, is given reporting the methodÂ’s efficacy for different coding costs and sparsity measures.