1. A method for estimating high-order Mel Frequency Cepstral Coefficients, the method comprising: a) in an MFCC vector of length N having L low-order coefficients (LOC), initializing any of N-L high-order coefficients (HOC) of said MFCC vector to a predetermined value, thereby forming a candidate MFCC vector; b) synthesizing a speech signal frame from said candidate MFCC vector and a pitch value; and c) computing an N-dimensional MFCC vector from said synthesized frame, thereby producing an output MFCC vector.