I hear some too. Not consistent though. I thought it was just me. When I am in a noisy setting, it's not a problem, but when it's quiet, I find myself trying to turn down the earpiece volume only to find it is at minimum.
I get the same thing but only hear it in the earpiece, not when on speaker phone. Where can I find this "hearing aide" option. I'm new to thing phone but love it other than the hissing.