More information about hearing aid compatibility can be found at the FCC’s website: http://www.fcc.gov/cgb/consumerfacts/hac_wireless.html.
There are two sets of standards for compatibility of digital wireless phones with hearing aids. These standards are established by the American National Standard Institute (ANSI): an “M” rating from one to four for reduced radio frequency (RF) interference to enable acoustic coupling with hearing aids that do not operate in telecoil mode, and a “T” rating from one to four to enable inductive coupling with hearing aids operating in telecoil mode.
Phones with an M-Rating of M3 or M4 meet FCC requirements. M4 is the better/higher of the two ratings.
Hearing devices may also be rated for this type of interference but your hearing device manufacturer or hearing health professional will be able to assist you with gathering information about your hearing device.
Phones with a T-Rating of T3 or T4 meet FCC requirements and are more likely to work well for people who use hearing aids with telecoils. In this rating scale, T4 is the better/higher of the two ratings.
GCI defines the level of a phone’s functionality with the following phone types:
The following statement is valid for devices with a HAC rating other than “NA”:
This phone has been tested and rated for use with hearing aids for some of the wireless technologies that it uses. However, there may be some newer wireless technologies used in this phone that have not been tested yet for use with hearing aids. It is important to try the different features of this phone thoroughly and in different locations, using your hearing aid or cochlear implant, to determine if you hear any interfering noise. Consult your service provider or the manufacturer of this phone for information on hearing aid compatibility. If you have questions about return or exchange policies, consult your service provider or phone retailer.
Handsets with Wi-Fi calling capabilities may not have been tested for hearing aid compatibility in this calling mode.