1. A method for extracting voiced/unvoiced classification information using a harmonic component of a voice signal, the method comprising the steps of: converting, by a frequency domain conversion unit, an input voice signal into a voice signal of a frequency domain; calculating, by a harmonic-residual signal calculation unit, a harmonic signal and a residual signal other than the harmonic signal from the converted voice signal; calculating, by a Harmonic to Residual Ratio (HRR) calculation unit, HRR using a calculation result of the harmonic signal and residual signal; and classifying, by a voiced/unvoiced classification unit, voiced/unvoiced sounds by comparing the HRR with a threshold value, wherein calculating the HRR comprises obtaining a harmonic energy using the calculated harmonic signal and the residual signal, calculating a residual energy by subtracting the harmonic energy from an entire energy of the voice signal, and calculating a ratio of the calculated harmonic energy to the calculated residual energy.