No, with a 3.5mm jack, they wouldn't be sending audio to the USB port.
Look inside the jack with a strong light. Something may be stuck in there. If there is something, and you can stick a needle into it and work it out, the jack will work again. But if it's a bent connector in the jack (usually the one at the bottom), that can't be fixed - the jacks are sealed. So you'd have to have the jack replaced. (And be nice with an earphone jack, not rough with it. You can't expect a part that costs 50 cents retail to be very sturdy. (¼" open frame jacks could take a little more, and they could be fixed a little, but 3.5mm jacks are just too tiny and flimsy.)