1. A method of operating a motion-capture system, the method including: monitoring at least three vibration sensors coupled to a motion-capture system; and in response to detection of vibrations generated by contact of an object with a surface of a solid medium, tracking a position of the object by: detecting a first vibration through a first medium by a first sensor; detecting a second vibration through a second medium by at least a second and a third sensor; measuring a time difference of arrival (TDOA) of the second vibration at the at least second and third sensors with respect to a TDOA of the first vibration at the first sensor and mapping surface locations that satisfy the TDOA; calculating a distance from the object to the second and third sensor based on the respective TDOAs; and determining location information for the object relative to the sensors based on the mapped TDOA surface locations.