ARTICLE Parthasarathi_IJST(SPRINGER)_2011/IDIAP Robustness of Group Delay Representations for Noisy Speech Signals Parthasarathi, Sree Hari Krishnan Rajan, Padmanabhan Murthy, Hema A EXTERNAL http://publications.idiap.ch/attachments/papers/2011/Parthasarathi_IJST(SPRINGER)_2011.pdf PUBLIC IJST (Springer) 14 4 2011 This paper demonstrates the robustness of group delay based features to additive noise. First, we analytically show the robustness of group delay based represen- tations. The analysis makes use of the fact that, for minimum-phase signals, the group delay function can be represented in terms of the cepstral coefficients of the log-magnitude spectrum. Such a representation results in the speech spectrum dominating over the noise spectrum, both at low and high SNRs. Further, we ex- perimentally demonstrate the robustness of the representation on a voice activity detection (VAD) task, comparing a group delay based VAD algorithm with standard VAD methods as well as a magnitude-spectrum based method.