Ok, this is strange. Day before yesterday I received a call on my 920. While in the call, I immediately noticed that my ear speaker sounded distorted as if it had blown out. Very bad sound quality! The distortion was so bad that the case of the phone would actually vibrate! After the call, I called another number to check out the sound quality....same thing occurred - distortion. And, it has been that way on every call since. Now for the strange part! All saved voice mails on my phone that were recorded prior to the sound becoming distorted plays fine! There is NO distortion when playing those saved voice mails. All voice mails recorded since day before yesterday and all calls have the distorted sound. There is no distortion if I listen to a call on speaker phone...it sounds fine. But, to listen to call or voice mail on the ear speaker is horrible! I've tried turning the phone off and on, and doing soft resets but the problem will not go away. Went to the ATT store with it and it blew the little dudes mind. Anyway, ATT is sending me a replacement phone. Once it gets here I'll hard reset the old one and see if it clears up, but I really don't look for it to.
I sent mine in to Nokia for the same issue, they couldn't duplicate it - when i got my phone back (same phone) it didn't have the issue and then about a week later it came back. I'm hesitant to send it back again. The only plus side was the I sent mine down with a piece chipped off my housing, and when it came back the chip was gone (new housing but old internals - same IMEI was listed)
Mine has started to play up as well. Need to keep volume under 6 or I cannot understand anyone talking on the other side. Not having much luck with Nokia phones at the moment I had my 900 repaired 3 time for a faulty microphone.
I'm going to be sending mine back to Nokia again for the receiver (and can feel battery shift inside if phone is slightly shaken). We have no ATT warranty centers in Alaska so I just go through Nokia directly. See what round 2 with them goes like.