42. A speech recognition system, comprising: a sound classifier that includes at least one non-transitory processor-readable medium and at least one processor communicatively coupled to the at least one non-transitory processor-readable medium, and that analyzes each of a plurality of frames of audio, classifies a first number of the frames of audio as speech, classifies a second number of the frames of audio as non-speech, forms a hypothesis based on the audio; and adjusts a threshold at which a recognized hypothesis is either rejected or accepted based at least in part on the first and the second numbers of frames.
43. The speech recognition system of claim 42 wherein, the sound classifier receives input from at least two microphones.