Palmfish,
The A/V Receiver’s manual does show analog “Tape In/Out” connectors, so that will be worth a try before I explore anything else. So thanks for that!
The AV receiver is a fairly low end Onkyo, with the manual showing: “5.1ch Home Theater/ HT-SR600 / AV Receiver (HT-R340)”. Probably 8ish years old and purchased on a close out deal back then. A significant improvement over the TV’s speakers, yet probably already obsolete. Looking at the back of the unit (as well as the manual), I see no other audio outputs (just the speaker wires). The headphone jack does mute all speakers (and no overriding menu instructions that I can find). It has zero HDMI ports, btw.
The TV is a 5 or 6 year old Panasonic 720p Plasma: TC-P50X1. It does have an Optical Digital Audio Out, however no sound is currently reaching the TV’s speakers. Those speakers show as “On”, but no sound is present even when they are ramped way up with the TV’s remote.
My older son is the IT tech in the family and keeps us up and running. He seems to think some of the newer AV Receivers have a HDMI “Audio Return” that could pipe all audio back to the TV if desired. If that’s correct it might be a better solution down the road - allowing for a cleaner hook up for the Resound (or similar) streamer. Any thoughts on that angle?
ETA: My IT guy (son #1) thinks we tried the Analog Tape-Out with wireless headphones at one point - with no joy. It seems they only work if the input from the sending device(s) is Analog. [I’m probably doing a poor job of relaying his comments - I’m hard of hearing, after-all. :]