Abstract: An electronic stethoscope includes an acoustic sensor assembly having a plurality of microphones arranged in an acoustic coupler to provide a plurality of pick-up signals. The electronic stethoscope also includes a detection system to communicate with the acoustic sensor assembly and to combine the plurality of pick-up signals to provide a detection signal. The electronic stethoscope also includes an output system to communicate with the detection system. The acoustic coupler uses a compliant material that forms an acoustically tight seal with a body under observation.