US Patent 7209569 Earpiece with an inertial sensor

A communication device includes an earpiece housing adapted for fitting to an ear of a user such that the earpiece does not block the canal, an inertial sensor operatively connected to the earpiece housing for sensing positional changes of the user's ears, a processor operatively connected to the inertial sensor and disposed within the earpiece determining presence of an alert condition at least partially based on positional changes, and a speaker operatively connected to the processor.