To provide a voice detection controller which can reduce the power consumption of a voice processor by performing voice detection adaptively to environment.

An input signal is converted by a rectifier 101 into an amplitude signal, a threshold is found by a low-pass filter 102 and an amplifier 103, and the quantity of variation in amplitude is found by a band-pass filter 104 and a rectifier 105. A comparator 106 compares the found variation quantity with the threshold and judges that the input signal possibly includes a voice when the variation quantity exceeds the threshold. Then a timer 107 outputs a control signal for a specific time and the voice processor is placed in operation.