One thought that led to two...thoughts are like rabbits...
Kind of on the fence about whether to try a new one or just live with it, but I just got a Bold 9650, and I've got a background hissing noise when calling. The hissing isn't anywhere else (music player, ringer, etc). It does sound like the normal kind of background hiss that I think all phones in existence have, just normally it's very faint or almost non-existent. Just on this phone it's more pronounced than I've heard on other phones.
Not sure if anyone else has noticed this, and whether it's a Bold problem, or a Verizon signal problem (wouldn't surprise me, it looks like there's some complaints about some android phones having the same problem too, leading to related theory below), or what. Kind of annoying because it's the only problem I have, and exchanging phones is about as fun as root canal, so I fear the dreaded scenario of exchanging the phone and getting the same problem or the new phone having a new problem. Although it is an annoyance, I might just live with it, because even though I hear the hiss, I can hear people perfectly fine, and usually I can only hear the hiss in quieter places. Overall, I think the clarity on the phone is better than any other cell I've had. I guess I'm just trying to get some input as to whether the problem would be worth the exchange, and whether this is an observed problem.
Of course, here's my related theory: newer phones have better sound. Used to be that cell phones had fairly crappy sound, cell phone signals (let's face it) had crappy sound, the point being that both cell phones and phone signals were fairly crappy, so it sounded just fine to us because that's what we had. Now, the sound on cell phones are getting better and more detailed, although, despite the cell phone companies best efforts, the quality of calls over even the newer technology is not quite keeping up with what the newer cell phones can produce sound-wise. Meaning all the little details in a cell phone call that used to not be heard (or at least not very much) is now amplified much more, leading to my sort of problem. Meaning...I'll just have to live with it.
Just a thought off the top of my head. Have you tried updating your PRL? Calling *228 and selecting option 2 might help. Let us know. Also, check in the options under Phone>Enhanced Audio and make sure the Automatic Volume Control is set to Disabled. That might be causing the problem.