An acoustic apparatus without increasing noise etc. even when plural directional microphones collect sounds from a place of the same distances is provided. Sound signals output from the microphone arrays are subjected to phase shift by phase shift circuits 211A to 211H, and the sound signals are combined by an adder 212. The phase shift circuits 211A to 211H performs phase shifts according to installation positions of the microphone arrays. The phase shift circuit 211A makes the shift 0 degree, the phase shift circuit 211B makes the shift 45 degrees, the phase shift circuit 211C makes the shift 90 degrees, and sequentially to the phase shift circuit 211H, the shifts are made according to rotational angles.