Professor Humphrey has particular research interests in the areas of medical ultrasound and underwater acoustics. Common themes running through his research include the understanding and application of non-linear acoustics and the laboratory measurement of physical acoustic phenomena including scattering. His main research interests include: · Nonlinear propagation, streaming and imaging in medical ultrasonics; · Ultrasonic heating and propagation in biological media; · Parametric arrays and their application to acoustic measurements in the laboratory; · Acoustic transmission and reflection properties of isotropic and anisotropic materials; · Scattering from objects and methods of measuring and predicting the scattered field for regular and irregular bodies; · Numerical modelling of transducers and fields.