According to this Thread https://discussions.apple.com/thread...rt=15&tstart=0
the issue is solved in 5.1.

But what about the 5.0.1 Jailbreak users who don't want to update to 5.1

Will it be possible to track down the patch and put it on Cydia?

Im my case i allready replaced my iPhone with Apple, made a fresh restore to 5.0.1 before it was to late ... and now again ... sometimes i can't hear the called person.

I don't really want to update to 5.1 but the issue is really annoying ...

[Edit] Maybe a Baseband only update? If someone can tell me how, i will test it [\Edit]