Passive acoustic sensing of walking

Acoustic sensing is expected to have a wide variety of practical applications. Sensing of human walking based only on passive acoustic information was studied experimentally. A simple microphone array consisting of four omnidirectional microphones and a common methodology of signal processing were employed to detect the positions of footsteps. The performance of the system was examined by evaluating the success rate and the spatial error of localization (position estimation) for footsteps in an indoor environment. The results showed that the system was capable of localization and tracking of footsteps within a radius of 3–4 m on the floor. The system can estimate the stride length, speed, and direction of the walking. The performance of real-time localization of footsteps was also evaluated.