Some answers arrive only after every outside voice becomes quiet enough.

Some answers cannot compete with input. They are quiet, they arrive slowly, and any amount of external voice will drown them out, which means they are unavailable to anyone whose days have no gaps. The answer is not being withheld; it simply cannot be heard at that volume.

If a question has been unresolved for a long time, try giving it silence rather than more research. A long walk with nothing playing, a morning with no input. The answer may surface on its own, and if it does not, at least you will have given it the only conditions in which it could.