193FCC Hearing Aid Compatibility (HAC)Regulations for Wireless DevicesThe U.S. Federal Communications Commission (FCC) hasestablished requirements for digital wireless mobile devicesto be compatible with hearing aids and other assistivehearing devices.When individuals employing some assistive hearing devices(hearing aids and cochlear implants) use wireless mobiledevices, they may detect a buzzing, humming, or whiningnoise. Some hearing devices are more immune than othersto this interference noise, and mobile devices also vary in theamount of interference they generate.The wireless telephone industry has developed a ratingsystem for wireless mobile devices to assist hearing deviceusers find mobile devices that may be compatible with theirhearing devices. Not all mobile devices have been rated.Mobile devices that are rated have the rating on their box ora label located on the box.The ratings are not guarantees. Results will vary dependingon the user's hearing device and hearing loss. If your hearingdevice happens to be vulnerable to interference, you may notbe able to use a rated mobile device successfully. Trying outthe mobile device with your h earing device is the best way toevaluate it for your personal needs.M-Ratings: Wireless mobile devices rated M3 or M4 meetFCC requirements and are likely to generate less interferenceto hearing devices than mobile devices that are not labeled.M4 is the better/higher of the two ratings. M-ratings refer toenabling acoustic coupling with hearing aids that do notoperate in telecoil mode.T-Ratings: Mobile devices rated T3 or T4 meet FCCrequirements and are likely to generate less interference tohearing devices than mobile devices that are not labeled. T4is the better/higher of the two ratings. T-ratings refer toenabling inductive coupling with hearing aids operating intelecoil mode.Hearing devices may also be rated. Your hearing aidmanufacturer or hearing health professional may help youfind this rating. Higher ratings mean that the hearing deviceis relatively immune to interference noise.Under the current industry standard, American NationalStandards Institute (ANSI) C63.19, the hearing aid andwireless mobile device rating values are added together toindicate how usable they are together. For example, if a
