1. A conference mixer, comprising: an input stream receiving unit configured to receive a plurality of input streams of data packets from a corresponding plurality of conferees connected to the conference mixer; a spectral voice activity detection (VAD) unit configured to, for each of the input streams, generate and output a spectral VAD decision indicating whether a frame comprising data packets is voice; a turbo VAD unit configured to generate and output a turbo VAD decision that indicates for a frame comprising data packets which of the input streams is active, the turbo VAD decision being based on the spectral VAD decisions for each of the input streams and a power-based decision indicating whether an estimated instantaneous power level of a frame comprising data packets is greater than a power threshold for each of the input streams; and a finite state machine (FSM) unit configured to select which of the input streams to output as an active stream based on a plurality of the turbo VAD decisions corresponding to a plurality of frames in the input streams.