This provision is an "objective immission " control. It regulates the site of the sound source while the Sound Reproduction Devices section regulates the devices that create the sound. It can regulate the sound levels received by "involuntary" listeners in the surrounding community as well as the sound levels received by "voluntary" listeners. If the latter aspect is incorporated, limiting internal sound levels often resolves community noise impact. Los Angeles (Article 2, Section 112.06)requires warning signs and limits noise exposure to 95 dB(A) at any position normally occupied. Seattle, WA {Section 25.08.501} considers the sound emitted to be in violation if the sound is "plainly audible" within a dwelling from 10 pm to 7am; the need for a sound level meter is avoided. Chicago, IL {Section 11-4-2805} limits received sound levels to 55 dB(A) inside a residential dwelling unit but if the ambient is greater, the limit is 65 dB(A). If outdoors, the limit is "conversational level" at 100 feet from the property line. If the building is set back 20 feet from the property line, the allowable level is 84 dB(A)! Both of Chicago's limits apply from 10 pm to 8 am. Salt Lake health Department, UT {Section 4.5.11.(vii)} sets the limit at 95 dB(A) at a position that would normally be occupied by a patron and 100 dB(A) at other positions. They also require a sign stating WARNING: SOUND LEVELS ON THIS PREMISE [sic] MAY CAUSE PERMANENT HEARING DAMAGE. HEARING PROTECTION IS AVAILABLE. Anchorage, AK (Section 15.70.060.B.12) sets maximum levels for any patron at 90 dB(A).