1. A method of speech recognition, comprising the steps of: (a) receiving audio including user speech and at least some transient noise associated with the speech; (b) converting the received audio into digital data; (c) segmenting the digital data into acoustic frames; (d) extracting acoustic feature vectors from the acoustic frames; (e) evaluating the acoustic frames for transient noise on a frame-by-frame basis; (f) rejecting those acoustic frames having transient noise, wherein steps (e) and (f) include 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; (g) accepting as speech frames those acoustic frames having no transient noise; and thereafter (h) recognizing the user speech using the speech frames.