Following problem
Today it was raining and I didn't pay attention to it and my cell phone was full of rain drops. And I can hear everything great the sound is not a bit consumed or something like that but when someone calls me the one does not hear me sometimes and sometimes. Depending on how I hold my cell phone sometimes I don't know whether it's fixed
Must probably reset the thing to factory settings.
If this does not help, send it in for repair
How it works with Whatsapp voice messages.