Lizards, such as
, have a relatively simple peripheral auditory system structured as a pressure difference receiver with a strong broadband directional sensitivity. In this paper we take a lumped-parameter model of the lizard auditory system, convert the model into a set of digital filters implemented on a TDT StingRay digital signal processing module carried by a small mobile robot, and evaluate the performance of the robotic model in a phonotaxis task. The complete system shows a strong directional sensitivity for sound frequencies between 1350–1850 Hz and is successful at phonotaxis within this range. The performance of and assumptions underlying the model are also discussed.