My earpiece speaker has stopped working on my iphone since updating to ios 6.1.3

I have recently updated my iphone software to IOS 6.1.3 and now when I make a call the other person can only hear me when on loudspeaker or on Hands free in my vehicle. When the phone uses the earpiece speaker all the other person can hear is a loud whistling noise, has anybody else had this problem ? If so is there a remedy?