Ron-

When our club field was first put in, the potential irritating noise was perceived to be problem by some of the neighbors. That was the major obstacle we faced in establishing the field. We had to show the owning agency of the property that we could operate without creating a noise nuisance for them to have to answer to. The answer to most of your questions is yes, i.e., noise level survey at the boundaries, house-to-house interviews, requirement for testing every model for compliance with strict limits on sound emissions, etc.
Also yes re complaints from persons new to the area, that began before they closed escrow on the property, and yes to talking to them in a friendly manner. An invitation to them to join us for the annual family picnic at the site resulted in an additional complaint to county authorities about our 'partying' there. They complained to the Fire Dept about a fire hazard that our activity supposedly represented.

As for what 'the real issue' was/is, for all I know it may have been that she was having a difficult menopause. Whatever, it doesn't matter - we had to defend against all of the charges made, before the town planning group and the county supervisor's office. Fortunately we were well prepared, including demonstration that we were well within the limits on noise emissions specified in the ordinances. It would not have mattered if noise were the real issue or not - getting the charge dismissed as without merit was critical to retaining our field. That would have been next to impossible to do if we had started getting smart about noise issues after the complaints were made.

Abel