Implementation of a voice activity detection and comfort noise generation algorithm

Voice activity detection and comfort noise generation (VAD-CNG) algorithms are widely employed in packet voice communication systems to reduce transmission bandwidth. This paper is devoted to the investigation of effective implementations of a modified version of a well-established fixed-point data-dependent VAD-CNG algorithm of Nortel Network on a TMS320C5402DSK DSP board. Certain optimizations that target reduction in the implementational complexity of the algorithm are introduced. Experimental results show that over 80% of the reduction in the implementational complexity is achieved through the proposed optimizations, making it possible to incorporate such a VAD-CNG algorithm into a practical real-time voice communication system. A real-time audio codec system is built in the laboratory to demonstrate a real-time implementation of this algorithm.