Abstract: An ultrasonic sound echography technique is disclosed in which echo-masked zones of the workpiece are reduced by utilizing particular orientations of the beam of ultrasonic sound relative to formations in the workpiece. Echo-masked zones result from formations in the workpiece which reflect the ultrasonic sound waves back to the probe and therefore mask the much smaller echoes from anomalies, if any, in the workpiece. Instead of the conventional orientation of the beam, in which the scanning plane in which the beam lies is oriented perpendicularly to formations, the scanning planes are selected so as to be non-perpendicular with respect to such formations and to minimize the amount of masking echoes from the formations.