Electromagnetic interference of bone-anchored hearing aids by cellular phones

We report a case of electromagnetic interference between a bone-anchored he aring aid (BAHA) and a cellular phone. A 54-year-old women was successfully treated for severe mixed conductive and sensorineural hearing loss with a BAHA. Five years after implantation, the patient experienced a sudden feeli ng of dizziness, accompanied by a loud buzzing sound and by a sensation of head pressure while examining a digital mobile phone. During a subsequent e xperiment, the buzzing sound could be reproduced and was identified as elec tromagnetic interference between the BAHA and digital cellular phones. Seve nteen adult BAI-IA users from our clinic participated in a subsequent surve y. Of the 13 patients with some experience of digital cellular phones, II r eported hearing annoying noises elicited by these devices. However, no othe r sensation, such as dizziness, was described. Owing to the increasing numb er of users of both hearing aids and cellular phones, the incidence of elec tromagnetic interference must be expected to increase as well. Although to date there is no evidence that such interference may be harmful or dangerou s to users of conventional or bone-anchored hearing aids, unexpected interf erence can be a frightening experience.