A middle ear hearing aid transducer is provided. The middle ear hearing aid includes: first and second permanent magnets arranged such that the same poles face each other; a coil separated a predetermined distance from the outer surfaces of the first and second permanent magnets, and surrounding the...http://www.google.es/patents/US6735318?utm_source=gb-gplus-sharePatente US6735318 - Middle ear hearing aid transducer
