I updated to software 4.1 on my 3gs iphone but still the same.

Is there a way to adjust the volume of the my voice maybe the mic is just to sensitive for me. I have tried to press the volume on the side of the iphone but nothing appears to happen?? Does it matter if I re-pair the phone again??
I have never done that. So basically at rest there is a little background noise present, while the x5 is moving loud "wind tunnel" background noise??? Everything closed (windows, roof, sunshade) and a/c / heat also off.