Guangji Shi

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A dual-microphone speech-signal enhancement algorithm, utilizing phase-error based filters that depend only on the phase of the signals, is proposed. This algorithm involves obtaining time-varying, or alternatively, time-frequency (TF), phase-error filters based on prior knowledge regarding the time difference of arrival (TDOA) of the speech source of(More)
A technique usingg the time-frequency phase information of two microphones is proposedd to estimate an ideal time-frequency maskk usingg time-delay-of-arrival (TDOA) of the signal of interest. At a signal-to-noise ratio (SNR) of 0dB, the proposedd technique usingg two microphones achieves a digit recognition rate (average over 55 speakers , each speakingg(More)
—In this paper, we analyze the effects of uncertainty in the phase of speech signals on the word recognition error rate of human listeners. The motivating goal is to get a quantitative measure on the importance of phase in automatic speech recognition by studying the effects of phase uncertainty on human perception. Listening tests were conducted for 18(More)
—This paper proposes a phase-based dual-microphone speech enhancement technique that utilizes a prior speech model. Recently, it has been shown that phase-based dual-microphone filters can result in significant noise reduction in low signal-to-noise ratio [(SNR) less than 10 dB] conditions and negligible distortion at high SNRs (greater than 10 dB), as long(More)
A multi-microphone time-frequency speech masking technique is proposed. This technique utilizes both the time-frequency magnitude and phase information in order to estimate the Signal-to-Noise Ratio (SNR) maximizing masking coefficients for each time-frequency block given that the direction (or alternatively, the time-delay of arrival) of the speaker of(More)
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