Abstract: A system comprises error microphones disposed in a predetermined pattern to capture audio signals including speech and one or more reference sensors to capture a reference noise signal from a noise source. A portion of the reference noise signal is removed from the captured audio signals to generate partially processed audio signals, which are paired to form signal pairs. For each signal pair, a modified cross-correlation vector, with effects of low frequency contents removed, is generated, then converted to a rotated angular domain cross-correlation vector based in part on a physical angle associated with locations of an associated pair of error microphones. The rotated angular domain cross-correlation vectors are summed, and a weighting vector is applied to the sum to identify direction information of a desired audio signal associated with the speech. The directional information is utilized to beamform the partially processed audio signals and output the desired audio signal.

Abstract: Embodiments of the present disclosure relate generally to systems and methods for reducing sound in vacuum toilets. In one example, multiple rinse injections are used at appropriately timed intervals in order to reduce the vacuum flush sound levels.

Abstract: A system and method of reducing noise in an enclosure is disclosed. The method includes receiving at least one reference signal; receiving pressure signals from no more than two substantially orthogonally placed pairs of acoustic sensors, where one pair of acoustic sensors is in the x-direction and one pair of acoustic sensors is in the y-direction, and where the acoustic sensors are placed in a plane which is substantially parallel and in proximity to an inner surface of the enclosure; using the pressure signals and the reference signal to generate an output signal to minimize energy density at a location of the acoustic sensors; and sending the output signal to an acoustic actuator.