Have you tried other headphones to determine the one's your currently using are not defective?
he's not having an issue with the headphones, but with the iphone jack. try what C DM said, above, should do it...
I understood that. It was a suggestive option to the OP, being I experienced the same issue on my previous iPhone. To which, indeed, WAS my headphones.
Get a long pin and have a poke about. It's amazing what you find in there. I found large pieces of pocket fluff.Been busy at work all day. It just started to work again magically. Maybe it has to do with the software update. Going to install pb 5 now