134• Should read and follow the directions from the manufacturer of your implantablemedical device. if you have any questions about using your wireless phone withsuch a device, consult your health care provider.For more information see, http://www.fcc.gov/oet/rfsafety/rf-faqs.htmlHearing Aid Compatibility with Mobile PhonesWhen some mobile phones are used near some hearing devices (hearing aids andcochlear implants), users may detect a buzzing, humming, or whining noise. Somehearing devices are more immune than others to this interference noise, and phonesalso vary in the amount of interference they generate.The wireless telephone industry has developed ratings for some of their mobilephones, to assist hearing device users in finding phones that may be compatiblewith their hearing devices. Not all phones have been rated. Phones that are ratedhave the rating on their box or a label on the box.The ratings are not guarantees. Results will vary depending on the user’s hearingdevice and hearing loss. If your hearing device happens to be vulnerable tointerference, you may not be able to use a rated phone successfully. Trying out thephone with your hearing device is the best way to evaluate it for your personalneeds.M-Ratings: Phones rated M3 or M4 meet FCC requirements and are likely togenerate less interference to hearing devices than phones that are not labeled. M4 isthe better/higher of the two ratings.T-Ratings: Phones rated T3 or T4 meet FCC requirements and are likely to be moreusable with a hearing device’s telecoil (“T Switch” or “Telephone Switch”) thanunrated phones. T4 is the better/higher of the two ratings. (Note that not all hearingdevices have telecoils in them.)Hearing devices may also be measured for immunity to this type of interference.Your hearing device manufacturer or hearing health professional may help you findresults for your hearing device. The more immune your hearing aid is, the less likelyyou are to experience interference noise from mobile phones.Other Medical DevicesIf you use any other personal medical devices, consult the manufacturer of yourdevice to determine if it is adequately shielded from external RF energy. Yourphysician may be able to assist you in obtaining this information. Switch your phoneoff in health care facilities when any regulations posted in these areas instruct you to