A Primer on Hearing Aid / Mobile Phone Compatibility

Hearing aids and mobile phones haven’t always gotten along as well as they do now. The complex electronics in both devices often caused static, lost words or squealing interference noises. Thankfully, improvements in technology and new government regulations have made the issue “Will this phone work together with my hearing aid?” simpler to answer. The regulations mandated new labeling requirements and ratings that help you to easily find a mobile phone that works well with your hearing aid.

The first thing you need to understand is that hearing aids operate in two different modes – microphone or “M” mode, and telecoil or “T” mode. In M mode, the hearing aid uses the internal microphone to detect sounds and amplify them. 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. Currently, approximately 60% of hearing aids sold in the United States have a telecoil or T mode.

The rating system for these two modes of hearing aid operation uses a scale that ranges from the lowest sensitivity (1) to the highest sensitivity (4). To be labeled as hearing aid compatible (HAC) a cell phone must carry a minimum rating of M3 or T3.

Hearing aids themselves also carry M and T ratings to indicate their sensitivity and ability to block interference in each mode. 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 cell phone users. A combined rating of 4 is considered usable for brief calls, but may not be suitable for extended phone use.

This combined rating system makes it easy to shop for a mobile phone online, because it easily allows you to determine how compatible it 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.