Health and Safety Information 143In the above example, if a hearing aid meets the M2 level ratingand the wireless phone meets the M3 level rating, the sum of thetwo values equal M5. This is synonymous for T ratings. Thisshould provide the hearing aid user with "normal usage" whileusing their hearing aid with the particular wireless phone."Normal usage" in this context is defined as a signal quality thatis acceptable for normal operation.The M mark is intended to be synonymous with the U mark. TheT mark is intended to be synonymous with the UT mark. The Mand T marks are recommended by the Alliance forTelecommunications Industries Solutions (ATIS). The U and UTmarks are referenced in Section 20.19 of the FCC Rules.The HAC rating and measurement procedure are described in theAmerican National Standards Institute (ANSI) C63.19 standard.Other Medical DevicesIf you use any other personal medical devices, consult themanufacturer of your device to determine if it is adequatelyshielded from external RF energy. Your physician may be able toassist you in obtaining this information. Switch your phone off inhealth care facilities when any regulations posted in these areasinstruct you to do so. Hospitals or health care facilities may beusing equipment that could be sensitive to external RF energy.VehiclesRF signals may affect improperly installed or inadequatelyshielded electronic systems in motor vehicles. Check with themanufacturer or its representative regarding your vehicle. Youshould also consult the manufacturer of any equipment that hasbeen added to your vehicle.Posted FacilitiesSwitch your phone off in any facility where posted notices requireyou to do so.M3 + M2 = 5 T3 + T2 = 5
