Hearing Aid Compatible Cell Phones
The Federal Communications Commission, demands that all cell phones, manufactured by the different vendors should be hearing aid compatible. Hearing aid compatible cell phones are RF interference free. However, it's not necessary that they can remove all sorts of interference. The FCC has mentioned three types of ratings, that decide which are the hearing aid compatible cell phones. These ratings have been described briefly below.
T-Rating
T-rating or the Telecoil rating, determines which are the cell phones, that are compatible to the hearing aids used by the cell phone user. A T-rating of 4, referred to as T4, is considered to be most compatible with the hearing aids.
M-Rating
Cell phones with an M4 rating are considered to be most suitable for microphone use, by a person with hearing difficulties. M-rating stands for microphone rating. People, with hearing problems should use a cell phone that has an M rating of 3 or 4, as these cell phones reduce the sound interference, to the lowest level, on the utilization of the ear phone.
RF-Rating
This is a combination of M-rating and T-rating. Cell phones use radio frequency signals for the transmission and reception of sound. A combination of M-rating and T-rating is what defines the final RF rating and is the deciding factor in selecting the cell phone for people with hearing problems. A cell phone with M4/T4 rating is considered as the best option, as they are most compatible with the external hearing aids, as well as the ear phones, that come along with the cell phone. M3/T3, M4/T3 and M3/T4 are the other RF ratings that different cell phones may have.
However, using a cell phone with a high T-rating or M-rating is not the ultimate solution. For example, a cell phone with a T4 rating may reduce the RF interference but it has no control over the magnetic interference, caused by the cell phone battery or the display. In such cases, those hearing aids that do not give way to magnetic interferences, should be selected. Similarly, the cell phones that do not have their M-rating or T-rating mentioned in their manuals are not necessarily incompatible with hearing aid users.
When choosing a hearing aid compatible cell phone, test the cell phone at different locations before buying it. A cell phone with an M4/T4 rating may be considered as hearing aid compatible by maximum users but you may start encountering RF interference, when you are in an area with a bad network coverage. This happens because the cell phone then requires more power to connect to the tower. When shopping online, check out all the options before buying. Since in online shopping you do not have a direct access to the device, so the only option that is left for you is the M-rating and T-rating. A total rating of 6 or above, with the addition of M-rating and T-rating is best for hearing aid compatibility.
