Enhancement of reverberant speech using excitation source information

This paper proposes a method for the enhancement of reverberant speech using the knowledge of the excitation source of speech production. The degradation level in the reverberant speech is measured in terms of Speech-to-Reverberation component Ratio (SRR). From perception and processing point of view high SRR regions are important. Hence the proposed method identifies and enhances the speech in high SRR regions. The high SRR regions are identified using the Hilbert envelope of the Linear Prediction (LP) residual, which contains information about the excitation source of speech production. The Hilbert envelope of the LP residual derived from the reverberant speech is processed by the covariance analysis to derive the weight function. The LP residual of the reverberant speech is multiplied with the weight function to enhance the excitations of speech in the high SRR regions. The speech signal synthesized from the modified LP residual is found to be less reverberant.