US Patent 11061081 Wearable audio device

A wearable audio device with a magnetic field sensor that is constructed and arranged to sense the Earth's magnetic field. A magnet in the earphone, for example the magnet of the electro-acoustic transducer, produces a first magnetic field having a first magnetic field strength. A nulling magnet produces a nulling magnetic field along at least a first nulling magnet axis. The nulling magnet is configured to reduce an influence of the first magnetic field on the magnetic field sensor. The first nulling magnet axis, the first magnet axis, and the first sense axis are aligned.