This provision is a "subjective immission" control. It can contain a "plainly audible" term or a curfew. It is applied to commercial facilities using a sound system to "deliberately" propagate mostly speech, but also music. Most cities have provisions relevant to this subject. Lakewood, CO (Sections 9.52.06 and 09.52.160) used "plainly audible" as a regulatory tool and prohibits the sounding of bells, or chimes from 10pm to 7am. Charlotte, NC (Section 15-69(a)(4)) limits levels to 60 dB(A) at 50 feet from 9am to 9pm and 50 dB(A) at other times. Indianapolis, IN (Section 391-505) addresses broadcasts from aircraft. Connecticut (Section 22a-69-1.7) exempts bells, carillons, and chimes from religious facilities.