Farmington Hills, MI Noise Ordinances: Decibel Limits (2026)

Sec. 17-101(b) (Method and units of measurement) requires that all measuring equipment and procedures conform to the latest American National Standards Institute (ANSI) specifications. Equipment must be properly calibrated before and after the measurement. Because sound waves of the same decibel level sound louder or softer to the human ear depending on frequency, an A-weighted filter constructed in accordance with ANSI specifications must be used, and all results are expressed in Db(A). Sec. 17-101(c) Table A sets the actual numeric caps. Residential uses - 60 dB(A) from 7:00 a.m. to 7:00 p.m., 55 dB(A) from 7:00 p.m. to 10:00 p.m., 50 dB(A) from 10:00 p.m. to 7:00 a.m. Business / office uses - 65 dB(A) from 7:00 a.m. to 7:00 p.m., 50 dB(A) from 7:00 p.m. to 7:00 a.m. Industrial (where all adjacent properties are industrial / business) - 70 dB(A) anytime. Industrial (where any adjacent property is residential) - 60 dB(A) anytime. All measurements are taken 'at any point on property adjacent or in close proximity to the lot or parcel on which the operation or activity is located' - that is, at the receiving / complaining property side. Sec. 17-101(d) (background noise) provides that where ambient background levels already exceed Table A, a source may match - but not exceed - the existing background level. Sec. 17-101(e) (intermittent / pure-tone sounds) is the key supplement to Table A: intermittent sounds or sounds characterized by pure tones may be cited even when the measured level does not exceed the cap, considering proximity to sleeping facilities, the nature of the use, time of day, and duration. This catches bass thumping, beeping reverse alarms, compressor cycling, and similar tonal sources that would otherwise underrun the meter. Sec. 17-101(f) (special exception) provides the relief mechanism - application to the Zoning Board of Appeals sitting as an administrative review board, supported by background noise study, predicted boundary-line levels, and justification. The Michigan Home Rule City Act (Act 279 of 1909) authorizes Farmington Hills to adopt this dB-based local police-power ordinance; Michigan has no statewide dB code so the city table is the controlling numeric framework. MCL 750.167 (disorderly persons) is the state misdemeanor backstop available without a meter reading.