An apparatus (100) and method is provided that identifies and tracks a relative location and movement of an object in a three-dimensional space. The sensing unit includes a processor (122) for communicating a coordinate information of the object within the three-dimensional space. The method includes emitting a pulse from a first transducer (101), estimating a time of flight from a reflection signal received by a second transducer (102), and determining a location and relative movement of the object from the time of flight measurements. The sensing unit can provide touchless control via touchless finger depression actions, finger slide actions, finger release actions, and finger hold actions.