Noise from Specific Sources in Montgomery County, MD (2026)

COMCOR 31B.00.03.04(a)-(b)

The maximum permissible sound level at the property line for the outdoor unit of any heat pump or air conditioner located on residential lots less than 12,000 square feet in area must not exceed 60 dBA. If the sound is determined to be a tonal noise as defined in 31B.00.03.03, the maximum permissible sound level at the nearest property line must not exceed 55 dBA.

Montgomery County Code § 31B-5

(a) Maximum allowable noise levels. (1) Except as otherwise provided in Sections 31B-6(a), 31B-6A, and 31B-8, a person must not cause or permit noise levels that exceed the following levels: ... Non-residential noise area 67 62 ... Residential noise area 65 55 ... (b) Noise disturbance. A person must not cause or permit noise that creates a noise disturbance.

Montgomery County Code § 31B-5(c)(1)

Sounding a horn or other signaling device on any motor vehicle on private property except: (A) in an emergency; or (B) as a danger warning signal during daytime hours if the device complies with noise level limits. (2) Operating a sound-producing device on public streets for commercial advertising or to attract public attention. (3) Selling anything by outcry. (4) Loading, unloading, openi...

Montgomery County Code § 31B-5(c)(7)

(7) Operating power equipment mounted on a motor vehicle or operating other devices powered by a generator or a motor vehicle. (1996 L.M.C., ch. 32, § 1; 2011 L.M.C., ch. 7 , § 1.) Editor’s note —See County Attorney Opinion dated 10/6/00 indicating that long-term parking on public streets is prohibited in certain circumstances, but not based on the size of the vehicle. See County Attorney Opin...

Montgomery County Code § 31B-5(a), (c)(4)

(c) Examples. The following examples illustrate common noise-producing acts that violate this section if they exceed the noise level standards set in subsection (a) or create a noise disturbance. The examples are illustrative only and do not limit or expand the noise level or noise disturbance standards of this section: (1) Sounding a horn or other signaling device on any motor vehicle on priv...

Montgomery County Code § 31B-2

Prominent discrete tone means a sound, often perceived as a whine or hum, that can be heard distinctly as a single pitch or a set of pitches. A prominent discrete tone exists if the one-third octave band sound pressure level in the band with the tone exceeds the arithmetic average of the sound pressure levels of the 2 contiguous one-third octave bands by: (1) 5 dB for center frequencies of 500 ...