So you got a new nano-SIM card which is not manually cut? If this is the case, did you recently update your phone software? Are you sure it's not a coverage issue?
Do you mean that you hear the counterpart bad or vice versa? Could you run some tests on your device via Diagnostics (Settings > About phone > Diagnostics) to exclude problems related to your speaker/microhpone?
The receiving is Bad. The phones from my wife, and from my darunter have at the same place and with the same provider a good receiving and my sony has noch receiving.
Do you have a bad reception everywhere or at a specific place? If it's everywhere, I suggest that you visit nearest service center to have the phone examined by a technicain since you have tried another SIM-card. Hard to say from here if it's any hardware issue that causes this problem. You can contact your Local support for information about nearest service center and/or how to proceed with this in the best possible way.
