THE SCIENCE AND APPLICATIONS OF ACOUSTICS - H. H. Arnold ...

13.12 Guidelines and Regulations in the United States 349costs $400 and the offender’s audio equipment gets confiscated as contraband.That equipment is then destroyed by the police (Lorain Morning Journal, 2003).Motorcycles and other recreational vehicles also can be troublesome to communitiesaround the world. In an informal survey of 33 motorcycles, audiologicalresearchers at the University of Florida found that nearly half of them producedsounds about 100 dB when throttled up—equivalent in intensity to a loud rock concertor a chainsaw. At the Institute for Sound and Vibration Research (ISVR) at theUniversity of Southampton, UK, it was found the noise levels under motorcyclehelmets can be quite high. Above 65 km/h (40 mph) the wind noise generated byairflow over a motorcycle and rider exceeds the noise level from the motorcycleitself. In Montana, Section 61-9-418 (2003) of the state code requires that all motorcyclesor quadricycles operating on the streets and highways must be equippedat all times with noise suppression devices, including an exhaust muffler, in goodworking order at all times. In addition, all motorcycles and quadricycles must meetthe following noise level limitations, on the basis of measurement of 50 ft fromthe closest point of the motorcycle or vehicle:(a) any cycle manufactured prior to 1970: 92 dB(A)(b) any cycle manufactured after 1969 but prior to 1973: 88 dB(A)(c) any cycle manufactured after 1972 but prior to 1975: 86 dB(A)(d) any cycle manufactured after 1974 but prior to 1978: 80 dB(A)(e) any cycle manufactured after 1977 but prior to 1988: 75 dB(A)(f) any cycle manufactured after 1987: 70 dB(A).In New Hampshire, a House Bill 326 was introduced in the legislature in 2005 toban modification of a motorcycle to amplify or increase the noise level beyondthat emitted by the original equipment installed by the manufacturer. No straightpipe exhaust system is allowed; and no motorcycle shall be operated, which has anoise level of more than 100 dB(A) when measured 10 ft (3 m) or further from theexhaust pipe or muffler. Noise measurement is to constitute a part of the mandatoryregular vehicular inspection.Railroad Noise RegulationsIn the United States, regulations for railroad noise are published in Section 40,Part 201, and Section 49, Part 210, of the Code of Federal Regulations. Testmeasurements are conducted within a cleared level area 30 m from the track centerline. Locomotives are tested either in motion or stationary status using remote loadcells. Noise limits have been specified for locomotives manufactured after 1979:Stationary, idle throttle setting: 70 dB(A)Stationary. All other throttle settings: 87 dB(A)In motion: 90 dB(A).For rail cars, the limits are:Moving at speeds 83 km/h (50 mph) or less: 88 dB(A)Moving at speeds greater than 83 km/h: 93 dB(A).