-
They would be disclosed - formally through the PIF, should Harringtons have made any formal complaints about them to the freeholder or council etc.
If he hadn't made a formal enquiry, then they don't have to be disclosed. One person's noise issue is another persons non-issue, too.
(I hate noise BTW, and when we bought our place, I was going round there at nights before we put an offer in, to try to get a sense of what it was like. Always do your own research....)
Tricky because you've said there are noise issues, which is exactly the sort of thing they're trying to find out isn't it...