4. The speech recognition system of claim 3 wherein the i=1 to N.sub.1 line spectral pair frequencies are in the 0 to 400 Hz range.
3. The speech recognition system of claim 2 wherein the distance measure, d(.function.,.function.), between the speech input signal, .function., and the reference speech signal, .function., is defined by: ##EQU27## wherein .function..sub.i and .function..sub.i are the ith line spectral pair frequencies in the speech input signal and the reference speech signal, respectively, the constants .alpha..sub.1, .alpha..sub.2, .beta..sub.1 and .beta..sub.2 are set to substantially minimize quantzation error, and e.sub.i is the error power spectrum of the speech input signal and a predicted speech input signal at the ith line spectral pair frequency of the speech input signal.