The present invention provides an energy feature extraction method for
noisy speech recognition. At first, noisy speech energy of an input noisy
speech is computed. Next, the noise energy in the input noisy speech is
estimated. Then, the estimated noise energy is subtracted from the noisy
speech energy to obtain estimated clean speech energy. Finally, delta
operations are performed on the log of the estimated clean speech energy
to determine the energy derivative features for the noisy speech.