In addition to other provisions of Saf-C 3236, a motorcycle shall be rejected if it produces a sound greater than 106 decibels at a specific rpm pursuant to RSA 266:59-a.

The sound level measurement procedure to be adhered to is as cited in RSA 266:59-a (II-a).

The referenced sound level measurement procedure (for the balance of calendar year 2012) is to be in accordance with the provisions of the Society of Automotive Engineers (SAE) Recommended Practice SAE J-1287.

Effective calendar year 2013, New Hampshire’s law will require the sound level measurement procedure to be in accordance with SAE J-2825 (must reading that includes new maximum decibel limit of 92 decibels at idle)

The SAE J-1287 and J-2825 documents have all rights reserved and are protected by copyright. Therefore, it is recommended that all official motorcycle inspection stations possess/purchase their own copy of SAE J-1287 and J-2825 which set forth the required Instrumentation; Test Site; Procedure and Measurements.

The extent of information that representatives of the Division are to provide an inspection station as it pertains to required motorcycle sound level testing Instrumentation and the Test Site will be limited to the following:

1. A Type 1 or Type 2 sound level meter that meets the requirements of ANSI S1.4.*Although either Type 1 or Type 2 sound level meters may be used, it is strongly recommended that a Type 1 instrument be considered as it generally has lesser overall tolerance, better precision, which can result in more accurate measurements (as would be required when legal enforcement is to be carried out).
2. A sound level calibrator with an accuracy of plus or minus 0.5 decibel.
3. An engine speed tachometer or other means of determining engine speed.
4. An anemometer (wind measuring device) with steady-state accuracy of plus or minus 10% at 20mph along with a windscreen for the microphone which does not affect the microphone for more than plus or minus 1 decibel
5. The test site shall be a flat, open surface without other sound reflecting objects such as parked cars, buildings or hillsides within 16 feet in all directions of the motorcycle being tested.
6. The surface of the test site shall be paved or hard-packed earth, level within the typical slope of a paved street or parking lot without loose or powdered snow, plowed soil, grass higher than 6 inches, trees or other material within 16 feet in all directions.

Inspection Stations may obtain a copy of SAE J-1287 and/or J-2825 (for a fee imposed by the SAE) by contacting the SAE as follows:
Telephone # 877-606-7323
Email: CustomerService@sae.org
AE Web Address: http://www.sae.org