Up until recently, the sophisticated electronics of cell phones often interacted badly with the electronics of hearing aids, resulting in interference between the two devices that was perceived as static, squealing or whistling noises, or missing words. New government regulations, along with significant advances in both cell phone and hearing aid technology, have made this incompatibility uncommon. The regulations mandated new labeling requirements and ratings that help you to easily find a mobile phone that works well with your hearing aid.
Understanding the rating system requires a bit of knowledge about the modes that hearing aids can operate in. There is an M mode (which stands for microphone) and a T mode (which stands for telecoil). When your hearing aid is in M mode, it uses the built-in microphone to pick up audible sounds from around you and amplify them to make them easier for you to hear. In T mode, the hearing aid instead uses an inductive process to pick up electromagnetic signals inside the phone directly, without the need for a microphone. Roughly 60 percent of all cell phones sold in the United States have a telecoil (T) mode.
The two modes – M and T – are each rated on a scale of 1 to 4 where 1 is the lowest sensitivity and 4 is the highest. To be labeled as hearing aid compatible (HAC) a mobile phone must carry a minimum rating of M3 or T3.
Hearing aids and cochlear implants have a similar M and T rating system to certify how sensitive they are in each mode, and how resistant they are to radio frequency interference. If you know the M and T ratings for your hearing aid, to determine its compatibility with any mobile phone, just add the two sets of ratings together. A sum of 6 or more makes a solid pairing. That hearing aid and cell phone combination should work well for you. A sum of 5 is considered normal and should work fine for typical mobile phone users. If the combined rating is 4, this is thought of as acceptable but not very usable if you make a lot of extended phone calls.
If you are shopping for a mobile phone online, you can usually use this combined rating to determine how compatible the phone you are interested in buying will be with your hearing aid. A better approach, of course, would be to go to a store that allows you to “try before you buy,” and actually use the phone you want while wearing your hearing aid, in both M and T modes.
The site information is for educational and informational purposes only and does not constitute medical advice. To receive personalized advice or treatment, schedule an appointment.