What is the protocol of Police Officers who get called out for noise disturbances?

I think it may depend upon the discretion of the police officers responding as to what course of action they may take. They could just tell the neighbors to turn the noise down or they could give them a citation for excessive noise. If other neighbors also complain you may be able to bypass the police and talk to the prosecutor's office because even if the police wrote a citation, the prosecutor would have to be involved perhaps when the neighbors went to court and you may get better response if several of you get together to file a complaint. If there are any repercussion from your calls to the police you want to make sure that you document those as well. I lived in an apartment complex for a while when we had a problem with a tenant so everyone else got got together and went to court together to get the guy evicted. You probably can't get those neighbors evicted but if you all go to court and complain, perhaps paying fines may convince him to turn down the volume. By the way, if that is a rental property you may want to notify the landlord as well since often excessive noise can also mean excessive property damage in rented property.