Thank you very much for your advise dewy78.
I solved this one, just before Christmas. I found Logitech make a headset specifically for the SONY PS3, called: the LOGITECH VANTAGE USB HEADSET (SONY PS3)
My son is pleased with it. It has one headphone and a pad the other side and a very good microphone that comes around very near to your mouth and comes with a spare ear phone pad.
You still only hear the person speaking to you through the headphone, the game play you hear via your open ear.
I got mine from: memory.com for £14.96 with p & p free.
I am not sure you can get this in the U.S.A. though dewy78, but you might have an outlet for Logitech, if you decide this method is ok for you.