Do you suffocate after a period of time in the rope trick? if not then you will have to describe 'why' that is.
One of the reasons could be because air passes in and out.. if that is so then there seems to be little reason for sound and smells to not be able to pass through as well
unless you want it to be a filter of some kind, but that is again going well outside of the spells stated effects.
(as for the infinite density thing, that doesnt work in a useful fashion. Both areas on each side have their own rules, just because you cant see its length and depth from the prime doesnt mean it doesnt exist.. and it certainly doesnt mean that you become 2d and have infinite density when you cross the boundary. Its dimensions 'do' exist. The things inside of it are taking up space. If you could see up into the rope trick then it would be like looking up into a cubby whole.. so no need to worry about dividing by zero
)
One of the reasons could be because air passes in and out.. if that is so then there seems to be little reason for sound and smells to not be able to pass through as well

(as for the infinite density thing, that doesnt work in a useful fashion. Both areas on each side have their own rules, just because you cant see its length and depth from the prime doesnt mean it doesnt exist.. and it certainly doesnt mean that you become 2d and have infinite density when you cross the boundary. Its dimensions 'do' exist. The things inside of it are taking up space. If you could see up into the rope trick then it would be like looking up into a cubby whole.. so no need to worry about dividing by zero
