I am trying to acoustically isolate a phone that has a very loud noise. Unfortunately it has preset volume levels and the volume cannot be decreased continuously ... but in a specific way (at levels)

This is a big problem because in the other room there is a neighbor and the walls are very close and are not soundproofed and I would not want to wake him up or disturb him

CAUTION:

The sound should be isolated to the left (adjacent roommate's room) and instead arrive intact in my direction.

What do you suggest?

I'm filling up some boxes to put on the left of the phone. What should I fill them with?
My room 1 meter x 5 meters long