Graham - I was joking about the noise of loud ukemi being a distractor (at least for me).
That said though, I've noticed that beginning students often do allow the noise from loud ukemi distract them. It seems the need to see where the noise came from is an ingrained response.
None of my military training has addressed this specifically, but I've talked to those who have received training concerning this response. For example, training soldiers to drop to the ground when a loud noise occurs nearby, instead of standing up and possibly becoming injured or even worse, losing your head!
Perhaps Colleen can elaborate more on the importance of not letting noise become a distractor on the battlefield
Have a good day!