My phone has a buzzing sort of noise that you can hear on a call, it doesn't seem to be coming from the earpiece, more from the 3G chip or something.. it's actually more clear if you listen on the back, middle of the phone and you don't have to be on a call to hear it, when the phone is downloading data it is present.
It seems to be something to do with 3G as over wifi it's fine
There's a few threads on the Apple discussion forums and someone has recorded a youtube clip of the sound (can't post links yet)
I took it to the Apple store last night, they heard it and said it was a hardware problem and swapped it out, but the replacement has the same noise.... A lot of people on the Apple discussions are saying they've swapped multiple times and still have the issue in the new devices.
Mine isn't bad, but it's there and I can hear it during calls, just thought I'd see if many other people have the same issue?? I'm thinking I'll just live with it for a while and wait to see if the problem gets resolved, maybe there's a bad batch of phones out there, or it's just the way the phone is.
How are everyone else's phones?