A new Apple’s patent tells us that the company at this point works on the gesture-based commands determined with audio transducers on the corners of a given surface. That means that if you press or tap on a surface, the audio receivers would determine where and how you touched it. The application describes a microprocessor that can "interpret electrical signals generated by the one or more acoustic transducers as input." The idea is that these transducers detect a finger making contact with the chassis and register those vibrations as gestures. Now the company found five different ways how it could be done.