1. An electronic method of extracting speech features from signals for use in performing automatic speech recognition, the method comprising using a computer processor to perform: receiving a signal; performing a time-to-frequency domain transformation on at least a portion of the received signal to generate a frequency domain representation; dividing the frequency domain representation into a plurality of frequency bands; fitting a FDLP polynomial to each of the plurality of frequency bands; performing a frequency-to-time domain transformation to extract temporal envelopes from each of the plurality of frequency bands using the fitted FDLP polynomial; constructing spectral envelopes by taking a plurality of points at each of a plurality of time values in the temporal envelopes, wherein each of the spectral envelopes has points taken at a particular one of the time values; fitting a smooth envelope to each of the spectral envelopes; and generating at least one speech feature based at least in part on the temporal and spectral envelopes of each of the plurality of frequency bands.