Paper Info
Title
A Novel Expectation-Maximization Framework for Speech Enhancement in Non-Stationary Noise Environments
Abstract
Voiced speeches have a quasi-periodic nature that allows them to be compactly represented in the cepstral domain. It is a distinctive feature compared with noises. Recently, the temporal cepstrum smoothing (TCS) algorithm was proposed and was shown to be effective for speech enhancement in non-stationary noise environments. However, the missing of an automatic parameter updating mechanism limits its adaptability to noisy speeches with abrupt changes in SNR across time frames or frequency components. In this paper, an improved speech enhancement algorithm based on a novel expectation-maximization (EM) framework is proposed. The new algorithm starts with the traditional TCS method which gives the initial guess of the periodogram of the clean speech. It is then applied to an L1 norm regularizer in the M-step of the EM framework to estimate the true power spectrum of the original speech. It in turn enables the estimation of the a-priori SNR and is used in the E-step, which is indeed a logmmse gain function, to refine the estimation of the clean speech periodogram. The M-step and E-step iterate alternately until converged. A notable improvement of the proposed algorithm over the traditional TCS method is its adaptability to the changes (even abrupt changes) in SNR of the noisy speech. Performance of the proposed algorithm is evaluated using standard measures based on a large set of speech and noise signals. Evaluation results show that a significant improvement is achieved compared to conventional approaches especially in non-stationary noise environment where most conventional algorithms fail to perform.
Year
DOI
Venue
2014
10.1109/TASLP.2013.2290497
Audio, Speech, and Language Processing, IEEE/ACM Transactions  
Keywords
Field
DocType
expectation-maximisation algorithm,speech enhancement,E step,M step,automatic parameter updating mechanism,clean speech periodogram,expectation maximization framework,noise signals,nonstationary noise environments,speech enhancement,speech signals,temporal cepstrum smoothing algorithm,voiced speeches,Cepstral analysis,expectation-maximization,speech enhancement
Speech enhancement,Adaptability,Non stationary noise,Pattern recognition,Expectation–maximization algorithm,Computer science,Cepstrum,Speech recognition,Spectral density,Smoothing,Distinctive feature,Artificial intelligence
Journal
Volume
Issue
ISSN
22
2
2329-9290
Citations 
PageRank 
References 
2
0.39
18
Authors
3
Name
Order
Citations
PageRank
Daniel Pak-Kong Lun126641.09
Tak-Wai Shen2192.97
K.C. Ho31311148.28