Thanks for the input! I am most interested in a full-enclosure earmuff and will be using it with my soon-to-be-delivered 55" flat screen TV. I've been using PC speakers/PC headset w/3.5mm stereo audio plug.
I should have looked at the headset plug closer; it does indeed read -
Nexus
U-174/U
M9177/2-1
The link in Marc's post indicates 'helicopter' but doesn't say if low or hi impedance. But if it requires power, then it's useless to me for the TV but I'll still use it for gunfire.
My TV hearing problem may be aggravated by my room; it's mostly bare, and sound bounces all around and gives an 'echo' effect when watching DVD movies if I don't use headphones.