Hello and thanks for using Just Answer.
I am Al and am happy to assist you with your enquiry.
I am afraid that I would always advise clients to be brutally honest when answering the Property Information Form.
As the last incident was over 3 years ago, I would hope that any Buyer would not take issue with it, but if you do not disclose it, and then the new Buyer does have to report any noise at some future date, and their records show your reported incidents, and this is disclosed to your Buyer, they would have the right to sue you for Misrepresentation.
I would therefore suggest that you disclose the previous incidents.
Sorry this is not the answer you were looking for, but it would be better to disclose, rather than face possible legal action at some point in the future.
Can I assist you any further?