Determining Sound Source Orientation from Analytical Source Directivity and Real Multi-Microphone Recordings

We present a method to estimate the orientation of a directional sound source and experimental results illustrating its performances. The method requires recordings captured by an array of microphones at known positions with respect to the source as well as the source directivity. Experiments have been performed in an ordinary environment by using a Polaroid transducer as the sound source emitting a broadband signal in the ultrasonic range. Such an acoustic signal has similar structure to those used by bats to echolocate. Results show that method is precise provided that the source directivity ensonifies the microphone array sufficiently. Further developments of the method, and its ultimate application to the reconstruction of emitted bat calls from remote recordings, are discussed.