Whisper denoising in Joint Time-Frequency Domain based on Real-Valued Discrete Gabor Transform

Whispered speech can be effectively used for quiet and private communications over mobile phones and is also the communication means for ENT patients under a regime of voice rest. However, little progress has been made on the denoising of whispered speech in noisy environment because of its special acoustic characteristics. In this paper, we propose a whisper denoising algorithm in joint time-frequency domain based on real-valued discrete Gabor transform(RDGT). Noisy whisper is first transformed into the joint time-frequency domain by fast real-valued discrete Gabor transform. The MMSE based log-amplitude estimator is derived under speech presence uncertainty hypothesis. Clean whisper spectral is then estimated by inverse transform of RDGT. Experimental results show that the proposed algorithm is very effective in avoiding the musical residual noise and retaining weak speech components.