INCE-USA publishes or provides a set of reports and guides on issues concerning Noise Control Engineering.
This booklet provides information and advice on controlling noise and sound for people interested in and sensitive to the acoustical environment where they live.
The authors have served as consultants for more than four decades during which time they have been contacted by individuals and companies throughout the United States requesting assistance to address many interesting and challenging acoustical issues. This booklet for homeowners is based on that experience.
We define noise control as reducing unwanted intrusive sounds. Sound control on the other hand relates to steps that can be taken at home to enhance and improve desirable sounds such as those associated with music and entertainment systems.
In December, 1980, the U.S. Environmental Protection Agency (EPA) issued a federal regulation on the noise emissions of motorcycles under the authority of the Noise Control Act of 1972. Although EPA’s Office of Noise Abatement and Control (ONAC) was defunded in 1981, the regulation is still part of the Code of Federal Regulations (40 CFR 205). After 32 years of experience with the regulation, there is general agreement that it has not accomplished its intended goal of reducing motorcycle noise emissions.
While the regulation has served to insure that all motorcycles entering commerce from major original equipment manufacturers (OEM) are in compliance with the regulation, as written, there are unintended consequences once the product enters service, including modifications that negate the noise control elements installed by the OEM. These regulatory deficiencies would benefit from clarifications and revisions. Motorcycle design has changed, the test procedure has proven difficult to implement, state and local government enforcement is rare, and there is widespread use of motorcycle exhaust systems that are not compliant with the regulation. Excessive motorcycle sound has become the single greatest threat to American motorcycling’s future. It’s among the most controversial and potentially divisive issues in motorcycling.
This report is a summary of a roundtable sponsored by the INCE Foundation and the Noise Control Foundation that was hosted by the National Academy of Engineering on October 24, 2012. This report includes recommendations for revisions to 40 CFR 205 that will increase benefits to the public, and assist state, and local authorities as well as manufacturers of motorcycles and aftermarket exhaust systems in assuring compliance with the regulation. Participants at the roundtable included motorcycle manufacturers and exhaust system manufacturers, trade associations, a standards organization, federal, state, and local government agencies, noise control engineers, and the public.
At highway speeds, the major source of noise is the interaction between tires and the road surface. Highway noise barriers have been used for many years and are the preferred solution for reducing highway traffic noise. Federal Highway Administration regulations for highway traffic and construction noise abatement (23 CFR 772) currently consider only noise barriers as an abatement measure for highway noise. Through the end of 2010, the Departments of Transportation of 47 US States and the Commonwealth of Puerto Rico have constructed more than 2,748 linear miles of highway noise barriers at a cost of close to USD$5.5 Billion (in 2010 dollars).
However, pavement type can considerably reduce the noise generated from tire-road interaction. Yet considering pavement as a noise abatement measure is currently only allowed for pilot projects approved by the Federal Highway Administration.
Treatment of highway pavement is generally less costly than the construction of barriers, but the noise reduction achieved by a quieter pavement is typically less than the reduction from a well-designed barrier, at least for residents in the immediate vicinity of the barrier. However, quieter pavements produce a reduction of noise at its source, which means that it may be possible to increase the number of benefited receptors (the recipient of an abatement measure that receives a noise reduction at or above the highway agency’s chosen noise impact threshold value). A combination of barrier and pavement treatment may lead to cost-effective solutions to highway noise.
To evaluate the effectiveness of quieter pavements, a reliable measurement method for tire/road noise is needed. The method that is currently favored is measuring On-Board Sound Intensity (OBSI). OBSI data are collected in conformance with AASHTO TP-76,3 the American Association of State Highway and Transportation Officials Standard Method of Test for Measurement of Tire/Pavement Noise Using the On-Board Sound Intensity (OBSI) Method.
This report on a follow-up workshop hosted by the National Academy of Engineering (NAE) to implement the findings and recommendations of its Technology for a Quieter America (TQA) report. The many references to occupational noise in the TQA report and the existence of both national and international regulations point to the importance of the control of occupational noise in America. The NAE currently has a project related to future manufacturing in the United States. To be successful, future manufacturing must create value by integrating manufacturing, design, and innovation. This effort has implications for the noise environment on future manufacturing floors, which has further implications for the design of both manufacturing facilities and manufacturing equipment.
Approximately a third of the workshop was devoted to the availability of effective low-cost techniques for the reduction of noise in industry, and design of low-noise machines for industrial use. The second third was devoted to techniques for reduction of noise through changes in industrial processes. The final third was devoted to the future manufacturing environment and its implications for new noise goals in manufacturing facilities. Lower noise goals will lead to the need to design low-noise machinery and equipment as well as low noise manufacturing processes.
This report on a TQA Follow-up workshop provides information on the progress made by noise control engineers in recent decades—specifically, in noise reductions of consumer products inside and outside the home, and industrial products for international and domestic markets. Projections are included on further noise technologies anticipated in the future.
Approximately one-third of the 25 workshop presentations summarized in this report addressed engineering noise control progress during recent decades for consumer products such as appliances, yard-care equipment, and automobiles. The second portion of the workshop presentations summarized here addressed a wide range of commercial and industrial products including gen sets, motors, compressors, electric transformers, valves, gears, off-road mobile machines, mining equipment, and natural gas pipelines, as well as military equipment and noise standards. This report includes a summary of findings based on the workshop presentations. The workshop agenda and a list of the 30 workshop attendees are provided as appendices. A professional court reporter was retained to produce a transcript for both days of the workshop. Presenters were provided the opportunity to review and edit their portions of the transcript. A professional science writer was retained to attend the workshop and prepare draft presentation summaries based on the transcript and the slides displayed at the workshop. The presenters were then provided the opportunity to review and edit the draft summaries of their presentations. Occasionally, presenters inserted post-workshop information for purposes of clarification and/or addition of insights. The TQA Editorial Committee reviewed and edited the presentation summaries to ensure clarity after which they prepared this report. It is expected that there will be continuing dialogue among workshop participants and interested parties and future TQA Follow-up workshops are expected during 2016 and beyond.