Audio mixer for multi-party conferencing in VoIP

Now-a-days, multi-party conferencing is an essential feature in the VoIP calls among desktop PCs, laptops. The additional voice processing module required for a conferencing when compared to a normal 2-way call is Mixer. Even though some algorithms are available in the literature, they lack in evaluating their performance. In this paper, different types of mixing algorithms are investigated and objective methods for evaluating their performance are proposed. Also, enhanced mixer algorithm based on an audio stream which has greatest amplitude among all the audio streams to be mixed is proposed. Comparison of all the algorithms is done in terms of quality and complexity. The proposed mixer algorithm out-performs all the mixer algorithms and the complexity of the proposed method is marginal. Also, different types of connection configuration of other voice processing modules with the Mixer are proposed for further quality improvement.