Includes bibliographies.Sonar beamforming is usually accomplished using a multi-element transducer array. To obtain high resolution, such a system is costly and complex. In contrast, many mammals are capable of good angular resolution using only a single active element surrounded by an irregular reflector – the ear. A study of monaural localisation was therefore undertaken, with a view to the development of a novel beamforming system which uses only a single active element. Computer simulations have shown that the direction of a source can be determined by cross –correlating the output signal spectrum with the known spectral responses of the receiving system for all angles