Method and apparatus for disturbing voice data using disturbing signal which has similar formant with the voice signal

A method and an apparatus for shielding a speaker voice by outputting a disturbing signal similar to the formant of voice data are provided to prevent people around a user from hearing call contents of the user by generating a disturbing sound according to formant information of voice. A frame generating unit(120) splits received voice data into frames having a certain size and converts the frames by using a frequency axis as a domain. A formant calculating unit(140) obtains formant information about a region where a signal intensively exists in the converted frames. A disturbing sound generating unit(150) generates a sound signal for disturbing the formant information with reference to the formant information. A disturbing sound speaker(160) outputs the sound signal at a point of time at which the voice data is outputted.