Health and Safety Information 193Hearing 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 ahearing aid meets the M2 level rating and the wirelessmobile device meets the M3 level rating, the sum of the twovalues equals M5.Under the standard, this should provide the hearing aid userwith normal use while using the hearing aid with theparticular wireless mobile device. A sum of 6 or more wouldindicate excellent performance.However, these are not guarantees that all users will besatisfied. T ratings work similarly.The HAC rating and measurement procedure are described inthe American National Standards Institute (ANSI) C63.19standard.Restricting Children's Access to YourMobile DeviceYour mobile device is not a toy. Do not allow children to playwith it because they could hurt themselves and others,damage the mobile device, or make calls that increase yourmobile device bill.M3 + M2 = 5T3 + T2 = 5