Speaker selection for tandem-free operation VoIP conference bridges

A conventional voice-over-internet protocol (VoIP) conference bridge reduces the speech quality due to tandeming the mixed multi-speaker signal with high compression speech codecs. One solution is to select and forward the compressed signal(s) to the endpoints, where they are decoded and mixed. In such arrangements, speaker selection is usually accomplished with an order-based approach which prevents listeners from interrupting the current speaker(s). This paper presents an alternative in which talking privileges are assigned based on order of activity and signal power. Subjective evaluations indicate that speaker switching is smooth, nearly transparent, and unanimously preferred over a VoIP conference with tandemed connections.