Jim K9YC wrote: >On 8/8/2013 6:19 AM, Bob W7AVK wrote: >> Most of the recent Hearing Aids have something called T Coil or >> similar feature. Very popular in Europe where folks gather like >> churches, etc. its essentially an inductive pickup. > >Yes, it is, but it has never gained traction in the US, where virtually all >systems for the hearing impaired use RF or infrared. I've used both >successfully in some pretty big spaces, but prefer IR for most venues. > The T-coil system works well in large spaces that have poor acoustics, and also for closed-front service counters in Banks (especially if there is a lot of noise on the customer side). In large spaces I sometimes use one hearing aid on the T-coil setting while the other is receiving the room in the normal way. This gives very useful "diversity reception". When listening to a single person speaking, the T-coil system often gives the more intelligible signal because it receives a direct feed from the podium or lapel microphone, unaffected by room acoustics.
>The Achilles Heel of these systems is stray magnetic fields, which can add 60 >Hz hum to your hearing aid. Further problems arise from the non-uniform magnetic field from the large induction loop. Listeners sometimes have to orient their heads in odd-looking ways to achieve a usable signal, while in high-signal areas there is also a risk of unexpected feedback from musical instruments that have magnetic pickups. 73 from Ian GM3SEK ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
