Living being presence detection system

A system for distinguishing between a first condition corresponding to a living subject being directly in contact with an object of interest, and a second condition corresponding to the absence of contact between the living subject and the object of interest. A transducer, which may be a MEMs sensor, is disposed in predetermined relationship to the object of interest and produces a transducer signal responsive to a pressure wave resulting from the living subject being directly in contact the object of interest. A database stores data corresponding to the first condition and may contain additional data corresponding to the second condition. A processor calculates an algorithm of a non-linear short-term frequency-selective energy distribution of the transducer signal over time to produce transducer signal data. An arrangement, which may be a human listener or a processor system, determines a threshold between the first and second conditions in response to the transducer signal data and the first and second data. The direct contact may be a tap or stroking contact by a living subject. The transducer can be disposed within, or on the exterior of, the object of interest.