Sounds like just your microphone, very easy to repair!
Buy a mic (eBay is cheap enough) & get a T6 screwdriver, that's all you'll need.
Remove your phone fascia back cover then the front cover, remove all 6 screws you can see & lift the phones circuit board out, you can see the microphone at the bottom, just flick it out with a screwdriver & pop the other in its place & put the phone back together.
ETA start to finish is about 5mins.
:o)
Craig
GATORS, November 2008
