In this paper, a procedure is described for finding the backscattered response of an elastic, solid particle in the nearfield of a high‐frequency ultrasonic transducer using aTmatrix to characterize the response of the scatterer itself. Numerical results are presented for spherical particles for both shaded and unshaded transducers. The particular application of interest is the monitoring of the vertical profile of sedimentary suspensions up to a meter above the abyssal ocean floor. For a 5‐MHz transducer, particles at distances of less than 50 cm from the transducer are in the complicated nearfield. The backscattered acoustic response of the sediment particles in a given volume as measured by an ultrasonic transducer is directly related to the concentration and size distribution of the particles.