29. A method for processing a spoken utterance consisting of a sequence of phonemes, said method comprising the steps of: detecting the frequency distribution of the energy of the utterance for a plurality of time intervals within the duration of the phoneme; dividing the detected energy into a plurality of frequency ranges; applying an automatic gain control independently to the energy of each frequency range; separating the output of each automatic gain control into a plurality of frequency bandwidths; deriving a short time constant energy spectrum representing the energy present in the phoneme as a function of frequency for a plurality of frequency distributions covering a first sequence of time intervals; deriving a long time constant energy spectrum representing the energy present in the phoneme as a function of frequency for a plurality of frequency distributions covering a sequence of time intervals which is longer than the first time intervals; deriving short time constant upward and downward sweep spectra representing the change in energy present in the phoneme from a lower to a higher and a higher to a lower frequency respectively as a function of time for a plurality of frequency distributions covering a second time interval; and deriving long time constant upward and downward sweep spectra representing the change in energy present in the phoneme from a lower to a higher and a higher to a lower frequency respectively as a function of time for a plurality of frequency distributions covering a time interval longer than the second time interval, whereby the spoken phoneme can be represented by the energy spectrum and the sweep spectra to facilitate speech recognition.
29. A method for processing a spoken utterance consisting of a sequence of phonemes, said method comprising the steps of: detecting the frequency distribution of the energy of the utterance for a plurality of time intervals within the duration of the phoneme; dividing the detected energy into a plurality of frequency ranges; applying an automatic gain control independently to the energy of each frequency range; separating the output of each automatic gain control into a plurality of frequency bandwidths; deriving a short time constant energy spectrum representing the energy present in the phoneme as a function of frequency for a plurality of frequency distributions covering a first sequence of time intervals; deriving a long time constant energy spectrum representing the energy present in the phoneme as a function of frequency for a plurality of frequency distributions covering a sequence of time intervals which is longer than the first time intervals; deriving short time constant upward and downward sweep spectra representing the change in energy present in the phoneme from a lower to a higher and a higher to a lower frequency respectively as a function of time for a plurality of frequency distributions covering a second time interval; and deriving long time constant upward and downward sweep spectra representing the change in energy present in the phoneme from a lower to a higher and a higher to a lower frequency respectively as a function of time for a plurality of frequency distributions covering a time interval longer than the second time interval, whereby the spoken phoneme can be represented by the energy spectrum and the sweep spectra to facilitate speech recognition. 30. The method of claim 29 wherein the separating step includes passing the detected energy through a plurality of low pass filters, and amplifying the output of adjacent low pass filters with difference amplifiers to separate the detected energy into a plurality of frequency bandwidths.