An electroacoustic transducer assembly and probe for emitting and receiving acoustic radiation beams. The transducer assembly comprising an array of electroacoustic transducers composed of a plurality of individual transducer elements each one being composed of an electroacoustic element. A means for defocusing a radiation pulse emitted from the transducer element is associated with each transducer element. The defocusing means is constructed and arranged to cause the radiation pulse to generate a substantially cylindrical or spherical acoustic field.
