"Planes, trains and automobiles"

This thesis documents the development of a vehicle detector based on sound recognition. It starts with an overview of current vehicle sound analysis and its shortcomings. Then a new approach is introduced: a sound source separation and recognition tool based on the principles of human hearing. The research question is whether this technique can be applied to vehicle detection and classification. We have answered this question by implementing a system that performs these tasks, and by evaluating its results. During the course of this project commercial and governmental interest arose and three specific applications were derived from a general system: a vehicle detector for busy city streets, an airplane detector and a vehicle detector for security and monitoring purposes. All the systems, though not fully optimized, show good detection scores. The last application even has such good, commercially acceptable, detection and classification results, that it has been turned into a fullyfledged system that has entered the beta-testing stage. The research has been conducted at the company Sound Intelligence from September 2002 until July 2003, under supervision of Dr. T.C. Andringa.