Ieee Journal of Selected Topics in Signal Processing 1 Compressive Sensing for Missing Data Imputation in Noise Robust Speech Recognition
Ieee Journal of Selected Topics in Signal Processing 1 Compressive Sensing for Missing Data Imputation in Noise Robust Speech Recognition
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通讯作者:
Jort Florent Gemmeke;Hugo Van Hamme;B. Cranen;L. Boves
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作者:
Jort Florent Gemmeke;Hugo Van Hamme;B. Cranen;L. Boves
—An effective way to increase the noise robustness of automatic speech recognition is to label noisy speech features as either reliable or unreliable (missing), and to replace (impute) the missing ones by clean speech estimates. Conventional im-putation techniques employ parametric models and impute the missing features on a frame-by-frame basis. At low SNR's these techniques fail, because too many time frames may contain few, if any, reliable features. In this paper we introduce a novel non-parametric, exemplar-based method for reconstructing clean speech from noisy observations , based on techniques from the field of Compressive Sensing. The method, dubbed sparse imputation, can impute missing features using larger time windows such as entire words. Using an overcomplete dictionary of clean speech exemplars, the method finds the sparsest combination of exemplars that jointly approximate the reliable features of a noisy utterance. That linear combination of clean speech exemplars is used to replace the missing features. Recognition experiments on noisy isolated digits show that sparse imputation outperforms conventional imputation techniques at SNR = −5 dB when using an ideal 'oracle' mask. With error-prone estimated masks sparse imputation performs slightly worse than the best conventional technique.