Felix,
I'd love to join you but boss is away and I'm running the show for a week so can't get any time off
It'll be 105db I've yet to do a quiet day at Oulton in 5 years, if you're worried you have a few options, they test one the first session only (usually) so either miss the first session and then ignore them when you go through they'll assume you've already been tested
or when they ask you to rev it to x revs only rev to around 3K as they're behind you with the noise meter they can't see the rev counter..