Suppressing aliasing noise in the speech feature domain for automatic speech recognition.
This letter points out that, although in the audio signal domain low-pass filtering has been used to prevent aliasing noise from entering the baseband of speech signals, an antialias process in the speech feature domain is still needed to prevent high modulation frequency components from entering the baseband of speech features. The existence of aliasing noise in speech features is revealed via spectral analysis of speech feature streams. A method for suppressing such aliasing noise is proposed. Experiments on large vocabulary speech recognition show that antialias processing of speech features can improve speech recognition, especially for noisy speech.
Deng
Huiqun
H
Institut National de la Recherche Scientifique, Université du Québec, 800 de la Gauchetière Ouest, Bureau 6900, Montréal H5A1K6, Canada. huid@ieee.org
O'Shaughnessy
Douglas
D
D001332:Automatism; D006801:Humans; D009622:Noise; D021641:Recognition, Psychology; D013067:Speech Perception