13. A method of analyzing and synthesizing speech signals as defined in claim 12 wherein said step of analyzing said speech signal to generate a voiced/unvoiced decision parameter further includes: monitoring said speech signal and counting the number of zero crossings in a predetermined time period; and comparing said number of zero crossings with a predetermined limit and generating an unvoiced decision parameter if said number of zero crossings is above said limit and generating a voiced decision parameter if said number of zero crossings is below said limit.
14. A method of analyzing and synthesizing speech signals as defined in claim 13 wherein said step of analyzing said speech signal to generate a voiced/unvoiced decision parameter further includes: providing an estimate register; comparing the output of said estimate register with the first autocorrelation coefficient produced by said linear prediction technique and setting said register to said first autocrorrelation coefficient value if said coefficient is equal to or less than said register value; and integrating the value in said register means if said coefficient is greater than said estimate register value; subtracting said estimate register value from said first autocorrelation coeficient value to generate a difference value; and comparing said difference value with predetermined upper and lower limits and generating a voiced decision parameter if said difference is greater than said upper limit and generating an unvoiced decision parameter if said difference signal is less than said lower limit.