My experience is using a neck loop plugged into the venue’s hearing assist receivers. This eliminates the need to have Telecoil installed in the venue.
I use a neck loop plugged into a hearing assist receiver with my hearing aids set to Telecoil. This eliminates having to install a Telecoil in the venue, but they must have a hearing assist system. My experience at church services is that sound is substantially better than using the hearing aids by themselves.
The manufacturer of the Therac-25, AECL, did not share customer incident reports with other customers when patients were injured. So, the hospitals believed that their incidents were isolated. This may have been legal, but was highly unethical.