Method for 3-Dimensional position calibration of audio sensors and actuators on a distributed computing platform. Vikas C. Raykar,  Rainer W. Lienhart, and Igor V. Kozintsev, US Patent number 6,941,246, 2005.

Three-Dimensional Position Calibration of Audio Sensors and Actuators on a Distributed Computing Platform. Vikas C. Raykar, Igor V. Kozintsev, and Rainer W. Lienhart, US Patent number 7,035,757, 2005.