This is a hard question to relay. What you're reading below isn't necessarily what the patron asked, it's just my understanding of what the patron asked - and I'm really not sure I ever understood correctly just what he was trying to do.
A patron came to the desk and said he had a pair of stereo earbuds, which were only playing sound on one side, and the guy at Radio Shack said he'd need to buy an adapter to make both sides play when he plugged into a mono jack (which he said our computers must have because he was only getting sound on one side). But instead of buying an adapter, the patron thought he could just go get another set of stereo earbuds and then plug one into the headphone jack on the front of our computers and the other into the jack on the back of our computers, and put whichever two of the four buds that worked into different ears and listen that way.
Most of this only marginally made sense to me. For one thing, the library headphones we offer for people to use all play sound out of both sides. I had no idea if our computer audio jacks were mono or stereo though, so we proceeded to do a little experimenting:
- First I plugged library headphones into the front, and both sides played
- Then I plugged them into the back, and again both sides played
- Next I left them plugged into the back as he plugged his earbuds into the front - and he had sound on only one side and the headphones had no sound
- Finally we plugged the earbuds in the back, and again he only had sound on one side
Since using the front jack shut off the back jack entirely, that shot down his idea of two simultaneous separate earbuds - which kind of deflated the whole situation. So after he sat down to work, I went back to the desk to try to figure out if our workstations had mono or stereo jacks. However, I poked all around inside the Control Panel and on the Dell website for our model PCs, and could not determine this one way or the other.
But what the internet did teach me is that you can tell from the plug if your headphones/earbuds are mono or stereo:
So knowing that, I decided to take a different tack - find a recording that was in stereo and see if the headphones play it correctly. A quick YouTube search found this:
Besides this being my new favorite YouTube video (the guy is so nice and polite!), it also told me that our computers definitely play in stereo. But, sadly, by this time the patron had left.
So now my working theory on what was happening is that the patron actually had mono earbuds, which apparently will only play one side when plugged into a stereo jack. Maybe this is what he was asking all along and I was just confused. He's one of our regulars though, so I'll watch for him and hopefully catch him before he buys some kind of adapter. It won't help with mono earbuds, but at least it'll save him some money. And I can also thank him for prompting me to learn all this stuff.