7. A speech processor for processing a speech signal, said speech processor comprising: a plurality of delay circuits, each receiving said speech signal f(t) as an input and generating a different time delayed version of said speech signal f(t-Td.sub.i) as an output; a plurality of correlator circuits, each said correlator circuit receiving said input speech signal f(t) and one of said time delayed speech signals f(t-Td.sub.i) and generating a correlation value indicating the amount of correlation between said speech signal f(t) and said time delayed speech signal; a comparator circuit receiving said plurality of correlation values and generating an autocorrelation of said input signal with time delayed versions of said speech signal, one correlation value being received from each of said correlator circuits; a pitch detector receiving said autocorrelation signal and identifying a pitch length for at least a portion of said speech signal; and an encoder receiving said pitch length and said speech signal and generating an encoded version of said speech signal wherein speech pitches of said speech signal are retained or omitted on the basis of said pitch detector input.
7. A speech processor for processing a speech signal, said speech processor comprising: a plurality of delay circuits, each receiving said speech signal f(t) as an input and generating a different time delayed version of said speech signal f(t-Td.sub.i) as an output; a plurality of correlator circuits, each said correlator circuit receiving said input speech signal f(t) and one of said time delayed speech signals f(t-Td.sub.i) and generating a correlation value indicating the amount of correlation between said speech signal f(t) and said time delayed speech signal; a comparator circuit receiving said plurality of correlation values and generating an autocorrelation of said input signal with time delayed versions of said speech signal, one correlation value being received from each of said correlator circuits; a pitch detector receiving said autocorrelation signal and identifying a pitch length for at least a portion of said speech signal; and an encoder receiving said pitch length and said speech signal and generating an encoded version of said speech signal wherein speech pitches of said speech signal are retained or omitted on the basis of said pitch detector input. 11. The speech processor in claim 7, wherein said pitch detector comprises a vowel pitch detector and a consonant pitch detector; said vowel pitch detector comprising means to receive said comparator output signal and calculating a vowel pitch length for high amplitude signals and large values of said autocorrelation function that are typical for vowel sounds; said consonant pitch detector comprising means to receive said comparator output signal and calculating a consonant pitch length for low amplitude signals and small values of the autocorrelation function that are typical for consonant sounds.