I stuck a small piece of magnetic tape on the sides of both of my Bernafon Veras 9CP hearing aids. That activated the t-coils and now I can clearly hear the TV through my aids via the Sennheiser SET840-S system. The sound is very clear although not as loud through my aids’ t-coil as it is when the 840-S plays through my headphones instead. With the TV set at the same low-moderate volume level, I need the volume control on the Sennheiser receiver set to 3.5 out of 6 with the headphones, 5 out of 6 with the t-coil. That doesn’t appear to be a problem, though, since the Sennheiser receiver is rechargeable.
I also discovered that you can boost the volume of the t-coils enormously if you drape the induction loop over your ears so they’re right close to your aids. It probably doesn’t look pretty (kinda like having your glasses on one of those neck cords), but if you need the extra volume for some reason, it’s there. I need my Sennheiser’s receiver volume set only at 2 out of 6 if I do this.
As I see it, the PROS of the t-coil over the headphones are: Watching a movie with my wife is more natural since I can easily hear her over the movie if she talks to me, like a person with normal hearing can, and I don’t have to pull off the extra device, i.e., the headphones, or otherwise mess with it or its cord.
The PROS of the headphones over the t-coils are: The headphones produce the TV sound in stereo and even with really-cheap headphones the sound quality is far superior to that of my t-coils—particularly when listening to a music channel, but even with voices. The t-coil sound is quite clear, but by comparison to even cheap headphones, the t-coil sound is tinny and, of course, only in mono. I also have more headroom in the Sennheiser receiver’s volume control with the headphones than with the t-coil, unless I’m willing to drape the induction loop over my ears.
Otherwise, the two options seem to work identically well. Both crystal clear with no static or drop outs.
So the next step is to have my audiologist set one of my four settable programs to manually switch on the t-coils, as Bernafon tech support tells me can be done. [EDIT: Apparently, that cannot be done with Bernafon Veras 9CP HAs with their automatic t-coil. The tech support guy must not have understood my question.]