TRANSDUCER ASSEMBLIES

A transducer assembly has a head (16) and a transducer element (14) contacting the rear of the head (16).In order to provide an output signal which has a positive value over a wide range of angles of incidence of shock or pressure waves to be detected, the transducer element (14) contact with the rear of the head 16 over a zone (22) which is smaller in cross sectional area than that of the rear of the head 16. The transducer element (14) is mounted in a metal tube (24) with a partly closed end (25) which electrically contacts the front face of the element (14). In order to position the transducer assembly positively and to inhibit unwanted shock or pressure waves reaching the element (14), the assembly has a series path of four interfaces of acoustic mismatch of shock or pressure waves, between said head (16) and a body portion (15).