Abstract: Embodiments include a method comprising forming a pipe including a first end and a second end by forming couplings between a plurality of sections of pipe. A loudspeaker is connected to the first end. The loudspeaker is a mouth simulator loudspeaker. A plurality of microphones are positioned a third distance inside an inside surface of the pipe using a receptacle positioned in the pipe a first distance from the first end and a second distance from the second end. An acoustic output is generated at the loudspeaker. One or more calibration filters are generated using outputs of the plurality of microphones produced in response to the acoustic output.

Abstract: Systems and methods are provided for detecting voiced and unvoiced speech in acoustic signals having varying levels of background noise. The systems receive acoustic signals at two microphones, and generate difference parameters between the acoustic signals received at each of the two microphones. The difference parameters are representative of the relative difference in signal gain between portions of the received acoustic signals. The systems identify information of the acoustic signals as unvoiced speech when the difference parameters exceed a first threshold, and identify information of the acoustic signals as voiced speech when the difference parameters exceed a second threshold. Further, embodiments of the systems include non-acoustic sensors that receive physiological information to aid in identifying voiced speech.