[–] CANCEL-CAT-FACTS 0 points 1 point 1 point (+1|-0) ago
Perhaps you should consider an accordion door -- Example. Good luck.
[–] TAThatBoomerang [S] 0 points 1 point 1 point (+1|-0) ago
I've considered this, but are they really any good at isolating sound?
[–] CANCEL-CAT-FACTS 0 points 1 point 1 point (+1|-0) ago (edited ago)
My friend has a door like this on his weirdly narrow bedroom door because he was getting woken up by neighbors making noise in the outside hallway, so it probably works.
[–] 6713906? 0 points 3 points 3 points (+3|-0) ago
The effectiveness of the solution depends on what frequencies you need to control. If you can line the side walls of your hallway with acoustic foam or thick tapetries it may help mute sounds reflecting through it.
Also, acoustic absorption within the kitchenette area will help minimize sound that goes down the hallway.
Although impractical, a "curtain" made of heavy futon would probably deaden sound but be difficult and annoying to get past.