by Neil Bauman, Ph.D.
A man wrote,
My parents attended a presentation at the Mayo Clinic in Rochester, MN, given by Juliette Sterkins, and she gave them your Center for Hearing Loss Help website info. My parents were very surprised at how well they could hear the presentation through their telecoil-enabled hearing aids and cochlear implant. I do have a few questions that do not seem to be answered on your web site.
1. While watching television with a telecoil system installed, will my parents be able to hear anything else other than the projected signal? For instance, me asking them a question?
2. I have a nice home theater surround sound system. Will they hear any of the sound from the speakers, or only what comes through the telecoil system?
3. I see on the web site that there are portable, personal neckloops. While walking down the street, listening through the telecoil to an iPod, will my parents still be able to hear the ambient traffic noise (car horns, sirens, someone talking to them on the street)?
4. Does the type of telecoil-enabled hearing aid/cochlear implant change the mix of telecoil signal and ambient sound allowed?
Good questions. My answers have to be general in nature as I do not know the specific makes and models of your parents’ hearing aids. Some hearing aids are not as flexible as others. However, let me explain how things typically work.
Typically, hearing aids have several memories (often 4 or so). Your audiologist can program whether the microphone or t-coil or both are turned on in any given memory.
One scenario might be where you have the microphones turned on (and t-coils turned off) when in memory 1, the t-coils turned on and microphones turned off in memory 2, and both the microphones and t-coils turned on in memory 3.
Here’s how they would use this in practice. For everyday listening, they’d use memory 1 so they’d hear the sounds around them.
When listening in any looped venue or when using a neckloop, they’d use memory 2 so they’d hear beautiful clear sound through their t-coils, and not any of the surrounding background noise.
When they want to both hear what goes on around them and via a loop, they’d use memory 3.
Therefore, to answer your 1st question, they could use memory 3 and could hear both you and the TV. They could do the same for question 2, but why would they want to since they’re hearing beautiful clear sound via the loop and using memory 2? It’s free of all distracting background sounds so they’d hear and understand their TV the best this way.
When they are using a personal device (iPod for example) and a neckloop, they could use memory 2 (t-coil only) if they wanted to block out outside sounds, or they could use memory 3 (both t-coil and microphones) if they wanted to also hear outside sounds.
The problem with using memory 3 in this case is that it would allow all the outside sounds to overpower the beautiful clear sound they are hearing via the t-coils in their hearing aids, thus largely negating the value of using a loop in the first place.
I find that I can’t hear (and understand) sounds coming from two sources at the same time. Thus, if I am listening to the TV via my loop system and t-coils, I would use memory 2 (t-coil only) and if my wife wanted to say something, I’d switch to memory 1 (microphone only). That way I hear and understand the best. If I had to hear her over the sounds from the TV, I wouldn’t understand either her or the TV.
You’d think that having the hearing aids set to both microphone and t-coil at the same time would be the best of both worlds, but in actual fact, it often turns out to be exactly the opposite. You see, the whole purpose of the loop system is to eliminate background sounds so you can hear only what you want to hear—beautiful clear speech or music.
Thus if your parents were walking down the street listening to their iPods via a neckloop and their t-coils (memory 2), they wouldn’t hear all the traffic noise including sirens, etc. But that is not a bad thing. They have their eyes to see what is happening around them while they listen to beautiful clear music.
In answer to question 4, in some hearing aids, I understand the ratio of microphone to t-coil is fixed. However, in others, I think the audiologist can set the ratio to whatever you want. But again, why would you do this? If they set the ratio to 80% t-coil and 20% microphone, you might not hear/understand someone talking to you, but if you set the ratio to 50-50 then the outside sounds would interfere with hearing/understanding via the t-coils. I think that is the case with cochlear implants too. I’m just not sure about this as things keep changing so much. This is a question to ask your parent’s audiologist about their specific hearing aids if they really want to try it.