According to one embodiment, an acoustic apparatus comprises an electro-acoustic transducer with a first function of converting an electric signal to an acoustic signal and a second function of converting an acoustic signal to an electric signal, the electro-acoustic transducer configured to convert a measuring electric signal to a measuring acoustic signal using the first function, and to convert an acoustic response signal responding to the measuring acoustic signal from an object to an electric response signal using the second function, a switch configured to switch the first function to the second function, or vice versa, and a switch controller configured to control a function switching of the switch in accordance with a sound source signal.