I have had several complaints from friends while on the telephone. While I hear them just fine, they complain the reception is lousy. I have tried turning the volume down, no luck. With or without "hotspot" open, no luck. With or without speaker on or off, no luck. This is my 3rd TB-others had other issues, which now are acceptable. Just the phone...I have the extended batt...if it matters.
Have all the phones that you have used had the same issues (all the Thunderbolts anyway)? If so, it just may be the noise-cancellation microphone that is different from previous phones used.
Please let us know. If you would like some specific help, I can call you if you PM me with your cell number.