problems with calling

[Kris315]

i got an iphone on february and it's unlocked, because I use it in estonia. A week ago started problems with calling and receiving calls. If somebody calls, i answer and it's totally quiet. I can't hear anything and the other part also can't. I haven't dropped my iphone and it also hasn't got wet. Sometimes after i've blown some air to the headphone output, i can make a call and hear again, but soon the problem continues.
what could be the problem and how could it be fixed?

 

[Phil A.]

Wirelessly posted (iPhone 16GB: Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420.1 (KHTML, like Gecko) Version/3.0 Mobile/4A102 Safari/419.3)

the iPhone sometimes gets confused and thinks the headphones are plugged in when they're not. It then routes all audio to the non existant headphones!
try plugging in and unplugging the phones. If that doesn't work try a restart.