there are three levels of regulation for stationary sound sources. The most basic is the general one associated with noise disturbance. (See Noise Disturbance below.) It is a very broad "subjective immission" control that has evolved from earlier disturbance of the peace provisions. Subjectivity can lead to arbitrary enforcement. The next level of regulation is less broad; it is an "objective immission" control that uses specific levels of sound considered to be a noise disturbance. Arbitrary enforcement is reduced. (See Maximum Permissible Sound Levels below.) In both cases, however, the person creating the sound may not be aware that his actions are in violation. The concept that a potential violator should have "fair warning" that his actions are in violation has led to provisions that address specific noise problems. The sections below list those that are found in community noise ordinances.