Iphone 4s crackling in ear speaker

https://discussions.apple.com/thread/3393647?start=870&tstart=0

I've heard the problem in 3 out of 3 phones, although the consistency in its severity is unclear to me.  The consensus is they all do it, although some insist swapping their phone mult times has eventually lead to a phone with either no issues or a significant improvement.  Apple states they've never heard of this issue, and their answer is to do a restore/firmware reinstall, although I've seen no concrete evidence it helps.  They said if that fails to help then its a hardware problem and they will offer a replacement.  From all i've read It seems to be related to cellular interference inside the phone. An actual call does not need to be made to hear it, you only need non-wifi transmission of data. The noise is not from the phones speaker, it's internal.

https://discussions.apple.com/thread/3393647?start=870&tstart=0

I've heard the problem in 3 out of 3 phones, although the consistency in its severity is unclear to me.  The consensus is they all do it, although some insist swapping their phone mult times has eventually lead to a phone with either no issues or a significant improvement.  Apple states they've never heard of this issue, and their answer is to do a restore/firmware reinstall, although I've seen no concrete evidence it helps.  They said if that fails to help then its a hardware problem and they will offer a replacement.  From all i've read It seems to be related to cellular interference inside the phone. An actual call does not need to be made to hear it, you only need non-wifi transmission of data. The noise is not from the phones speaker, it's internal.