From what I've seen, people in hyperfocus often seem to effectively lose their sense of hearing, too. Which is sort-of useful in a noisy office, but can be dangerous when going about your daily life.
The problem is that the converse can be true, this is true if you actually hit the hyperfocus trance but if you don't get there, the noise can actually distract you from ever getting there and if it is not a task you want to do, the noise is guaranteed to provide the needed distraction, to avoid the task all together.
