A hearing aid is provided with a a programmable, signal processing circuit electrically connecting an input system to an output system, a magnetic field sensor, and a selection circuit connected to the magnetic sensor. The selection circuit may be adapted to control at least one of the input system, output system, and the signal processing circuit, where the selection circuit in conjunction with the magnetic field is configured to select the system or circuit to control based a magnetic field strength received at the magnetic field sensor being one of at least three levels of magnetic field strength.