The caller can't hear clearly.

According to the situation you described, I suggest you change other contacts to see if the same phenomenon occurs. If the problem persists, I suggest you:

1. Check whether the third-party software is newly downloaded and installed on the mobile phone. It is possible that the software is not compatible with the mobile phone, so it is recommended that you try to uninstall it (Settings-Application Manager-Select Downloaded-Uninstall);

2. If it can't return to normal, it is recommended that you back up your mobile phone data (phone book, SMS, multimedia files, etc.). ) and restore the factory settings (Settings-Reset-Restore Factory Settings);

If the problem still exists, it may be that there is something wrong with the software of the mobile phone system. It is recommended that you take the three-guarantee certificate of your mobile phone and send it to the nearest Samsung service center for testing.

I hope it helps you!