A distributed conferencing system having a plurality of conferencing nodes
to connect groups of participants to a conference. Each of the
conferencing nodes provides for the connection of one or more
participants to the conference. Each node includes a DSP for distributed
signal processing. The node DSP includes: A signal measuring device for
measuring features of the signals from each of the participants, such as
power, zero crossing rate and short term energy and voice activity
determination and feature extraction from the signals of the participants
connected to each node. Each node has a single core speaker tracking
algorithm for determining the relative features of each of the number of
participant input signals. The speaker tracking compares the
characteristics of the speakers of the core and determines which speakers
are to be included and which speakers are to be excluded from
presentation to the other nodes in the conference. The core also has a
communication device for communicating the measured signal
characteristics for the included participant input signals to all other
conferencing nodes and for receiving the signal characteristics from
selected participants of the other nodes.