I'm just finishing up my private license and am looking forward to taking some friends up in a Cessna 172. I've invested in a nice aviation headset for myself, but, as none of my friends are pilots, they don't have headsets of their own. Even the cheapest aviation headsets (at least that I've found) are around $100; friends going up for an occasional flight don't want to spend that kind of money, and I certainly don't want to shell out for several spare headsets.
My question is, are there adapters available so that normal headphones could be plugged into a standard 2 jack connector? I have not been able to find any online. While certainly not too effective at reducing noise, this would at least give my passengers some comfort and would allow me to communicate with them without shouting during these short and infrequent flights. Worst case scenario, I could give them all earplugs, but it would definitely be helpful to have some kind of headset solution so that I'm not shouting through the sound of the prop and the earplugs and they're not shouting through my ANR.