Soundproofing-how can I avoid volume spreading?

I like to play some Fortnite at night and then my mother comes in because she hears me when I speak a bit louder. Our house is built thin. What can I do about it not so loud and / or that my mum does not hear me.

Speak quieter?

Depends on the nature of the house.

But what helps is to use egg cartons to surround a specific area.

But that only makes 1/4 to 1/3.

I'm not talking so loud. When I spend the night with friends and we talk about the volume of the room my mother hears it too.

Oh - can you maybe put a cupboard on another wall?