Voice/unvoice determination and dialogue enhancement

A dialogue enhancing method and apparatus for boosting formants of dialogue zones without changing sound zones are disclosed. The dialog enhancing method comprising: (a) includes calculating line spectrum pair (LSP) coefficients based on linear prediction coding (LPC) from an input signal; , (b) determining whether or not voice zones exist in the input signal on the basis of the calculated LSP coefficients; , and (c) extracting formants from the LSP coefficients according to whether or not the voice zones exist, and boosting the formants.