PURPOSE: To efficiently measure the incoming bearing of an acoustic signal with a hearing sound by employing a signal obtained from a plurality of microphones having a specified directivity set under the sea.

CONSTITUTION: This measuring apparatus is equipped with a nondirectional microphone 1 arranged to face the incoming direction of an acoustic signal, microphones 2 and 3 having a 8-shaped directivity whose directivities are arranged to intersect each other, a resolver 7 in which the 2-phase winding on the side of the stator is excited by the output of the microphones 2 and 3, a circuit 8 adapted to perform computation for the output of the winding on the rotator side of the resolver 7 and a amplification circuit 9 for giving the computation output to a speaker 10. The rotating shaft of the resolver 7 rotates and when the hearing sound reaches a specified level, the incoming bearing of an acoustic signal is determined from the angle of rotation of the rotating shaft of the resolver 7.