Does the town have a noise ordinance? I have found that trying to use the noise ordinance is often not effective.
See NH RSA 644:2, Disorderly Conduct. Specifically Section A, III (a). Note that the penalty after being asked to stop one time is a misdemeanor. This is part of the NH Criminal Code; it is not a local ordinance, which might not have effective penalties. Admittedly the RSA has subjective language, e. g., “reasonable” and “average”, but if the conduct is outrageous, it may be more effective.
http://www.gencourt.state.nh.us/rsa/.../644/644-2.htm