It’s funny. A lot of guys who play Hamlet played Romeo earlier in their careers. I wonder if any of them get to this line and suddenly feel tempted to say, “But soft, what light through yonder window breaks?” instead of “noise.”
Probably not. But this, “But soft, what…” is a lot less famous than that other one is.
It’s also a moment alone – just like Romeo.
It’s a “shut up” to himself.