Patent ID: 9025803
Filing Date: 2015-05-05
Classification: H04R

Abstract:
1. A hearing aid for delivering a sound to an ear canal and having a component generating an ambient magnetic field, the hearing aid comprising: a magnetic sensor configured to sense a sound signal being a sound magnetic field representing the sound, the magnetic sensor including: a telecoil configured to sense the sound signal; and a counter coil configured to allow for generation of a counter signal being a counter magnetic field having a counter direction approximately opposite to a direction of a noise signal being the ambient magnetic field; an active driver circuit coupled between the component and the counter coil, the active driver circuit configured to receive a current from the component and drive the counter coil using the received current, the active driver circuit including a current adjuster configured to adjust for an interference null by scaling the received current and passing the scaled current through the counter coil; a processor configured to process the sound signal; and a receiver configured to deliver the processed sound signal to the ear canal.