Hearing aids have not previously always worked effectively with mobile phones, because of electronic interference between the 2 devices that caused static, whizzing or screeching noises, or lost words. Fortunately, advances in technology and new government regulations have made the issue “Will this cell phone work 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. 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. The T mode is important when shopping for a phone, because at least 60% of hearing aids sold in the United States have one.
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 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 combined rating of 5 is thought of as normal, and suitable for most people. A sum of 4 is considered acceptable, but if you are a heavy cell phone user, you may be disappointed or frustrated with this choice.
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 mobile phone shop and test out a few different phone in real conditions.