To realize a voice detecting device less susceptible to noise level and capable of stably detecting voice zones in an input signal.

A noise level computing part 1 computes the noise level of an input signal, and a first threshold computing part 2 computes a power threshold and voice start-point correcting parameters corresponding to the noise level. A detection parameter computing part 3 computes voice detection parameters such as standard deviation of power, and a voice start-point detecting part 4 detects voice start points. A voice start-point correcting part 5 corrects the voice start points by using the voice start-point correcting parameters. A second threshold computing part 6 computes a voice detection parameter threshold corresponding to the noise level. A voice detecting part 7 detects voice zones by using the voice detection parameter threshold and voice detection parameters so as to cover input signals after the corrected voice start points.