(a) Continuous Sound.
(1) No person shall cause, suffer, allow, or permit the operation of any source of sound on any source property listed in 519.03(a) above in such a manner as to create a sound level that exceeds the sound level limits listed in Table I, as measured at any location at or within the property line of the receptor property. Sound pressure levels in excess of those established in Table I shall constitute prima facie evidence that such sound is in violation of this chapter.
TABLE I
MAXIMUM PERMISSIBLE SOUND LEVEL LIMITS dB(A)
Residential | Residential | Commercial | Industrial |
8:00 a.m. - 9:00 p.m. | 9:00 p.m. - 8:00 a.m. | 24 hours | 24 hours |
Noise sensitive | |||
24 hours | |||
60 | 50 | 65 | 70 |
(2) These limits may not be exceeded by any single incident representing the normal, usual operation of the sound source, during any three sampling intervals, the duration of which shall be no less than one half minute, within any one hour period. If the total duration of the sound under investigation is less than one and one half minute, the requirement for three measurements shall be waived. For example, if a motor fan belt were to squeal for twenty seconds upon starting, but the sound were emitted with regularity from this source, a single measurement shall be sufficient.
(3) Nothing in this section supersedes the requirements of employers to comply with the Occupational Noise Exposure Standard of the Occupational Safety and Health Administration (29 CFR Part 1910.95). Compliance will help conserve workers’ hearing, and reduce potential liability for the source.
(b) Impulsive Sound.
(1) Between 8:00 a.m. and 9:00 p.m. impulsive sounds, which occur less than ten times in an hour shall not equal or exceed 20 decibels above the permissible sound level limits in Table I. Impulsive sound which repeats ten or more times in any hour shall not exceed the permissible sound level limits in Table I.
(2) Between the hours of 9:00 p.m. and 8:00 a.m., impulsive sounds which occur less than four times in an hour shall not equal or exceed 20 decibels above the permissible sound level limits in Table I. Impulsive sound which repeats four or more times in any hour shall not exceed the permissible sound level limits in Table I.
(c) Amplified Sound Reproduction Device. If the source of sound is an amplified sound reproduction device, and the complainant states that the rhythmic bass component of the music is disturbing within their residence then the Noise Control Officer shall be authorized to take sound level measurements within the residence of the complainant. No person shall cause, suffer, allow, or permit the operation of any amplified source of sound in such a manner that it raises the total sound levels by the permissible sound level limits set forth in Table II when measured within the residence of a complainant. These sound level measurements shall be conducted with the sound level meter set for “C” weighting, “fast” response. Such measurements shall not be taken in areas, which receive only casual use such as hallways, closets and bathrooms. For the purposes of these measurements, the neighborhood residual sound level is that sound level which is measured in the residence when the sound source under investigation is not prominent, or in a room on the same floor that is relatively unaffected by the sound source under investigation. The C-scale is more sensitive to low frequency sound levels than the A-scale. An increase of 3 dB is perceived by humans as being perceptibly louder, while an increase of 5 dB is perceived as being plainly louder. At the lower bass frequencies of music an increase of 6 dB is perceived as a doubling of loudness.
TABLE II
AMPLIFIED SOUND REPRODUCTION DEVICE
MAXIMUM PERMISSIBLE SOUND LEVEL LIMITS
Indoors across a real property line
dB(C) ABOVE NEIGHBORHOOD RESIDUAL SOUND LEVEL
Weekdays 9:00 p.m. - 8:00 a.m. | All other times |
Weekends 11:00 p.m. - 9:00 a.m. | |
3 dB(C) | 5 dB(C) |
(d) Steady Pure Tones. If the sound source under investigation is a mechanical device, and is in the investigating Noise Control Officer’s opinion emitting a sound with a steady pure tonal quality, the permissible sound level limits in Table I shall be reduced by 5 dB(A). The sound emissions must be comprised of a single frequency or a narrow cluster of frequencies, which may be referred to as a whine, hum or buzz. The measured sound levels of such a source must not fluctuate by more than plus or minus 3dB. Such sound sources include, but are not limited to, heating, ventilating or air-conditioning units; refrigeration units; and transformers.
(Ord. 03-089. Passed 4-14-03.)