headphones showing up as recording device instead of playback device

When I plug my headphones into my laptop, for some reason they have started showing up under recording devices instead of playback devices, and no sound comes out of them. When I plug my headphones in and try to play music, the little bar that shows the audio level next to the device moves up and down as if audio is coming out of it, but they are silent. I'm using an Asus Zenbook UX31E with 64bit Windows 7. I've had this laptop for a year and a half with no problems. The sound works fine coming from the computer speakers, but not the headphones. I have tried they "show disabled devices" trick,

Question by Nick on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.