Hearing aids and mobile phones have not always gotten along as well as they do now. The complex electronics in both devices often caused static, dropped words or squealing interference noises. Technology improvements along with new regulations have largely eliminated this issue. Today cell phone – hearing aid compatibility isn’t the problem it once was. The regulations mandated new labeling requirements and ratings that help you to find a cell phone that works well with your hearing aid.
To understand how this rating system works, you should first understand the two modes that hearing aids work in – M mode (for microphone) and T mode (for telecoil). In M mode, your hearing aid uses its built-in microphone to pick up audible sounds from the environment and amplify them so that you can hear them. When the hearing aid is in T mode, instead of the microphone it uses its built-in telecoil to directly pick up conversations from inside the phone, in the form of electromagnetic signals. Roughly 60 percent of all mobile 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. No mobile phone or cordless handset sold in the United States can be sold as hearing aid compatible (HAC) unless it has a rating of at least 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. To determine the compatibility between your hearing aid and a mobile phone you are considering, just add the M and T ratings together; add the M rating of the hearing aid to the M rating of the phone and add the T rating of the hearing aid to the T rating of the phone. A sum of 6 or more makes a solid pairing. That hearing aid and cell phone combination should work well for you. If the combined rating is 5, this combination is considered normal and suitable for most regular phone use. 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. In the end, nothing beats a real world test so you may want to wear your hearing aid to the cell phone shop and test out a few different phone in real conditions.