Is there a simple way to stream sound from both my PC and my Android phone to the same set of headphones? I'm open to both hardware and software solutions, but software solutions would be better. I'd like to listen to music and notifications on my phone, but also hear sound effects and notifications on my work PC.
Personally, I've found software solutions to this kind of thing to be more hassle than they're worth. Do you mind if your devices are physically close to each other? If not, I recommend a cheap hardware solution:
You could buy a 3.5mm extension cable to give yourself more flexibility if you need your devices a little farther apart. All of these kinds of cables are basically the same; search around Amazon, or your online market of choice, for the deal that fits you best.