A handle is adapted to receive one or more fingers or a portion of the hand. A set of sensors is mounted on or near the surface of the handle. Each sensor associated with a different region of the handle. A detector is arranged to detect contact of one or more of the sensors, by one or more fingers or a portion of a hand, to generate an observed touch-point map for the handle for a respective sampling interval. A controller can generate a gain or control response ratio in the electrical signals outputted in response to the observed touch-point map matching or being substantially similar to a reference touch-point map, where the electrical signals are derived from movement or displacement of the handle by a user.