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Open Access

A Computationally Efficient Mel-Filter Bank VAD Algorithm for Distributed Speech Recognition Systems

  • Damjan Vlaj1Email author,
  • Bojan Kotnik1,
  • Bogomir Horvat1 and
  • Zdravko Kačič1
EURASIP Journal on Advances in Signal Processing20052005:561951

Received: 18 March 2004

Published: 30 March 2005


This paper presents a novel computationally efficient voice activity detection (VAD) algorithm and emphasizes the importance of such algorithms in distributed speech recognition (DSR) systems. When using VAD algorithms in telecommunication systems, the required capacity of the speech transmission channel can be reduced if only the speech parts of the signal are transmitted. A similar objective can be adopted in DSR systems, where the nonspeech parameters are not sent over the transmission channel. A novel approach is proposed for VAD decisions based on mel-filter bank (MFB) outputs with the so-called Hangover criterion. Comparative tests are presented between the presented MFB VAD algorithm and three VAD algorithms used in the G.729, G.723.1, and DSR (advanced front-end) Standards. These tests were made on the Aurora 2 database, with different signal-to-noise (SNRs) ratios. In the speech recognition tests, the proposed MFB VAD outperformed all the three VAD algorithms used in the standards by relative (G.723.1 VAD), by relative (G.729 VAD), and by relative (DSR VAD) in all SNRs.

Keywords and phrases

voice activity detectiondistributed speech recognitiontelecommunication systems

Authors’ Affiliations

Institute of Electronics, Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia


© Vlaj et al. 2005