Hearing aids have not in the past always worked well with mobile phones, because of electronic interference between the two devices that caused static, whistling or screeching noises, or lost words.Fortunately, advances in technology and new government regulations have made the question “Will this phone work with my hearing aid?” easier to answer. Government regulations introduces mandatory labeling requirements making it much easier to find a mobile phone compatible with your existing hearing aid.
The understand the labels, first you need to know that hearing aids can operate in one of two modes. Microphone mode is symbolized with an “M” and telecoil mode is represented with a “T”.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.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.T mode is standard in roughly 60 percent of all hearing aids.
Each of the two modes – M and T – have a standard sensitivity rating scale applied to them. The lowest sensitivity is 1 and the highest sensitivity is 4.To be sold in the United States as hearing aid compatible (HAC), a mobile phone or cordless handset must have 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.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.If you get a combined total of 6 or more, that is thought of as excellent, a combination of hearing aid and phone that will be highly usable.A total rating of 5 is considered normal and satisfactory to people with normal usage patterns.A combined rating of 4 is considered usable for brief calls, but may not be suitable for extended phone use.
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.