Having been the president of our HOA, despite numerous written rules, infractions occur, and an HOA board actually has very little power to enforce the rules other than fines leading to lien on the offending property. Infraction can continue until property is sold. In an effort to better enforce HOA rules, I came to rely on County code enforcement; letting them be the bad guy and also they have some serious enforcement capability. Not sure what noise ordinances are in place for city/county in this specific instance, but that would be a good place to start if issues arise.