Abstract: A method and apparatus for generating and detecting acoustic surface waves particularly useful in the non-destructive testing of materials. In this method, the acoustic surface wave is generated in the test sample by a generator transducer coupled to the test sample so as to cause the acoustic wave to impinge on it at the required critical angle. The acoustic surface wave is detected by a pair of spaced steel wedges having their narrow ends in contact with the surface of the test sample so as to detect the shear component of the acoustic surface wave and to generate bulk waves in the steel wedges which travel away from the plane of the contact surface to pick-up transducers.