Anyone else having issues with poor call quality/reception?

[coco727]

I've had the iPhone 5 for about 4 months now and I'm just starting to have this issue. When I call people, no matter how many times I say hello, they can't hear me. It's the same when people call me. When I answer, I can't hear them. Hanging up and redialing makes it better but it's still a little fuzzy. A friend of mine is blaming the Otterbox Commuter case I have on the phone but I've had the case on for about a week and a half and it initially was fine. I don't think it's the case so now I'm wondering if anyone else is having the same issue.