A sending conversant uses a sending communication device to transmit voice and body state information over a communication network to a receiving communication device used by a receiving conversant. Model based rendering is used such that the model is transferred from the sending conversant to the receiving conversant along with the transmitted data. The sending device includes means for sensing the body state of the sending conversant, collected as body state measurements. The sending communication device also includes means for detecting speech uttered by the sending conversant, such as an audio microphone. The detected speech and body state measurements are encoded in a temporally synchronized manner and multiplexed into a communication signal which is transmitted to the receiving device.