Scream and gunshot detection and localization for audio-surveillance systems

Abstract

This paper describes an audio-based video surveillance system which automatically detects anomalous audio events in a public square, such as screams or gunshots, and localizes the position of the acoustic source, in such a way that a video-camera is steered consequently. The system employs two parallel GMM classifiers for discriminating screams from noise and gunshots from noise, respectively. Each classifier is trained using different features, chosen from a set of both conventional and innovative audio features. The location of the acoustic source which has produced the sound event is estimated by computing the time difference of arrivals of the signal at a microphone array and using linear-correction least square localization algorithm. Experimental results show that our system can detect events with a precision of 93% at a false rejection rate of 5% when the SNR is 10dB, while the source direction can be estimated with a precision of one degree. A real-time implementation of the system is going to be installed in a public square of Milan.