Letter to Editor: Noise ordinances



To the Editor:

The Islander’s reporting of the noise arguments at Hall Quarry and Bar Harbor show a lot of effort going into feel good regulation but not one mention of a legally enforceable agreement.

Over the last 50 years there have been a plethora of court cases on noise ordinances. In general, the courts have adopted a strict technical standard that a noise ordinance must meet.

Human ear response to sound loudness is very nonlinear across the frequency spectrum. For noise effect on humans, measurements of the raw sound pressure level are converted to a human equivalent through application of an A-weighting function.

The levels are stated in decibels (dBA). Modern, low-noise appliances have a noise level of about 50 dBA. Hearing damage can occur with levels above 85 dBA.

This A-weighting is the legal basis for such laws in the U.S. through the American National Standards Institute (ANSI) and by international treaties to several UN-affiliated entities (ISO, IEC, ITU, etc.).

To my knowledge, the courts have consistently required that any noise ordinance must specify a dBA value; that the value must be reasonable, i.e. between 50 and 85 dBA; a time average specified; that a properly-trained person makes the measurements; that measurements are made with professional, calibrated instruments and that measurements are made 30 meters (~100 feet) beyond the property boundary containing the noise source.

A caveat: Any noise ordinance applies to your rowdy parties and the band at football games also.

Hoping this note will prompt more productive discussions.

Carl Brooks

Great Cranberry Island

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