In the past, the complex electronics of mobile phones often interacted badly with the electronics of hearing aids, resulting in interference between the two devices that was perceived as static, screeching or whistling noises, or missing words. Compatibility issues are now largely a thing of the past thanks to cell phone technology advances, hearing aid technology advances and government regulations.These 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. 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. T mode is standard in roughly 60 percent of all hearing aids.
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 or marketed as a hearing aid-compatible phone in the US, a cordless handset or mobile phone must have a minimum rating of T3 or M3.
In addition, many hearing aids (and cochlear implants) have a similar M and T rating to measure their sensitivity and their resistance to radio frequency interference. When shopping for a phone, to determine its compatibility with your hearing aid, simply add its M and T ratings together with those of the phone to create a combined rating.To ensure the highest quality, interference-free pairing, look for a sum of 6 or more.A combined rating of 5 is thought of as normal, and suitable for most people.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.
The rating system has created standards making it easier for hearing aid users to shop for a mobile phone online with confidence.If you are able to shop in a store that allows you to “try before you buy” and actually use the phone you want while wearing your hearing aid, that is of course a better idea.