The ultrasonic benchmark problem requires models to predict, given a reference pulse waveform, the pulse echo response of cylindrical voids of various radii located in an elastic solid for various incidence angles of a transducer immersed in water. We present a conceptually simple yet reliable numerical technique to determine these internal fields in any region of interest within the elastic solid for the specified angles made by the transducer in water. The technique, equivalent to evaluating the Rayleigh-Sommerfeld integral but through a computationally less demanding procedure, regards the transducer as made of elemental rectangular/square patches and uses the well-known expression for the radiation pattern of an elemental patch to obtain the total transducer radiation field. A ray-based method is adopted to propagate the elementary radiation field across a fluid-solid interface. The FBH is treated in terms of explicit patch element reflectors, its response is evaluated and validated with measurements. The P-wave scattering charactieristics of spherical voids are evaluated using the exact separation of variables method and the patch model for the transducer is used to determine their response. The advantages of the patch model for the transducer in the context of the benchmark problems in particular and non-destructive evaluation in general are indicated. © 2005 American Institute of Physics.