No person shall cause or allow the emission of excessive noise beyond
the boundaries of his or her noise district or zone so as to violate any provisions
of this chapter.
No person shall emit beyond his or her noise zone infrasonic or ultrasonic
sound in excess of 100 dB at any time.
In those individual cases where the background noise levels caused by sources not subject to this chapter exceed the standards contained herein, a source shall be considered to cause excessive noise if the noise emitted by such source exceeds the background noise level by 5 dBA, provided that no source subject to the provisions of this chapter shall emit noise in excess of 80 dBA at any time, and provided that this section shall not decrease the permissible noise levels permitted by the other provisions of this Article
IV.