The invention relates to an insonification device (100) comprising a plurality of elementary ultrasonic transducers (110) each comprising at least one electro-acoustic element (111) and distributed on a chassis (120, 140) so that the electro-acoustic elements (111) are distributed on a so-called front surface (120′) of the device (100) intended to be placed facing the medium to be insonified. According to the invention, as each transducer (110) comprises a longitudinal body (113) made in a heat conducting material at the so-called front end of which the electro-acoustic element (111) is placed, the chassis (120, 140) comprises a sealed cooling chamber (130) placed behind the front surface (120′), crossed by the bodies of the transducers (113) and intended to be gone through by a coolant fluid flow.