Nigerian parents and their phone call volume , why are they shouting?

My mother will call me at 7am on a Saturday and I can hear everything from her end. The kettle boiling, my father clearing his throat, the neighbour's dog. She is shouting like the person on the other end is in another country. Meanwhile I am holding the phone right next to my ear and my eardrum is threatening to resign.

I asked her why she does this and she said 'the network is not fine'. The network is fine, Mummy. You just don't trust the invention.

God when will Nigerian parents learn that volume does not equal clarity? 😭