13. A speech recognition system, comprising: an acoustic interface to receive audio including user speech and at least some transient noise associated with the speech; a pre-processor to pre-process the received audio, including segmenting the digital data into acoustic frames, extracting acoustic feature vectors from the acoustic frames, evaluating the acoustic frames for transient noise on a frame-by-frame basis, rejecting those acoustic frames having transient noise, and accepting as speech frames those acoustic frames having no transient noise, wherein the pre-processor rejects those acoustic frames having transient noise by assessing at least two time spaced samples within an acoustic frame to determine autocorrelation of the samples within the frame, and rejecting the acoustic frame if the autocorrelation is determined to be insufficient; and a decoder to recognize the user speech using the speech frames.
13. A speech recognition system, comprising: an acoustic interface to receive audio including user speech and at least some transient noise associated with the speech; a pre-processor to pre-process the received audio, including segmenting the digital data into acoustic frames, extracting acoustic feature vectors from the acoustic frames, evaluating the acoustic frames for transient noise on a frame-by-frame basis, rejecting those acoustic frames having transient noise, and accepting as speech frames those acoustic frames having no transient noise, wherein the pre-processor rejects those acoustic frames having transient noise by assessing at least two time spaced samples within an acoustic frame to determine autocorrelation of the samples within the frame, and rejecting the acoustic frame if the autocorrelation is determined to be insufficient; and a decoder to recognize the user speech using the speech frames. 15. The system of claim 13 , wherein the pre-processor rejects those acoustic frames having transient noise by comparing an acoustic frame to a preceding acoustic frame accepted as a speech frame to determine cross-correlation between the acoustic frames, and rejecting the acoustic frame if the cross-correlation is determined to be insufficient.