An acoustic signal processing apparatus (100) disclosed in the present application includes a detecting unit (120), a calculating unit (130), an accumulating unit (150), and a determining unit (160). The detecting unit (120) detects an acoustic signal that is contained in a sound input signal and that is generated by a human body. The calculating unit (130) calculates an effective volume indicating an effective volume of the acoustic signal detected by the detecting unit (120), based on the input signal. The accumulating unit (150) accumulates the effective volumes calculated by the calculating units (130) to calculate the accumulated effective volume. The determining unit (160) determines whether the accumulated effective volume calculated by the accumulating unit (150) has reached a predetermined threshold.