US Patent 7245732 Hearing aid

A digital hearing aid system includes a signal path with an input transducer, a signal processor and an output transducer, a part of the system being intended for delivering sound into an ear canal of a hearing aid user leaving the ear canal with an unobstructed cross-sectional area corresponding to a vent channel with a diameter of at least 3 mm or a total area of at least 7.07 mm2. The signal path is designed to have a signal delay less than 15 ms. The hearing aid signal path furthermore preferably includes means for providing an adaptive feedback compensation. The signal processor is adjusted to provide increased gain in low frequency areas.