Area Of Noise Control Research Articles

Remembering remarkable Larry H. Royster

Larry Royster was a dedicated scientist and engineer whose recognized contributions in the area of noise control and hearing conservation were by no means his only interests. After retiring, Larry's amazing mind was free to follow his fancy into a wide variety of topics. He measured countless phenomena and graphed the results, read nonfiction prodigiously and rated what he read, and wrote summaries for the public about what he was learning. He took up golf and amateur radio with zeal. Liberated from responsibilities that he had always taken quite seriously, he teased his friends and laughed with them. He also reflected on qualities of character that drove him throughout his teaching and research career. In this presentation I will share sides of Larry that were not obvious to many.

Demonstration hearing conservation program for construction workers in Washington State

Construction workers have traditionally been an ‘‘underserved’’ population in the area of noise control and hearing conservation. Approximately 500,000 of these workers are currently exposed to potentially hazardous levels of noise and little progress has been made to the U.S. to mitigate this exposure. A labor–management–professional team composed of members of the Washington State Building and Construction Trades Council, the Building Trades Labor Management Organization, the Center to Protect Workers’ Rights, and professionals in industrial hygiene, audiology, and medicine, have developed a ‘‘common sense’’ hearing conservation program to serve construction workers and employers. Initiated as a demonstration program in the State of Washington, the program is tailored to the U.S. construction industry. It will include worker and supervisor training using construction-specific materials, training in the fundamentals of construction noise control, fitting and training in the use of hearing protection devices, audiometric surveillance, centralized record keeping, and the evaluation of program effectiveness. Special emphasis is being placed on the use of readily available noise control solutions as well as hearing protection devices that will not degrade communication and the perception of warning signals. Program plans are currently being finalized and training will be initiated in December of 2000.

New initiatives in noise control reflecting on lessons from Arden House

In June 1972, the Acoustical Society held a conference on Acoustics and Societal Problems (CASP) at Arden House in Harriman, New York. Over 50 members participated in the 3-day conference, organized in seven task teams under the able general chairmanship of John C. Johnson. The 89-page report of this conference contains detailed assessments of needs and recommended actions in five scientific and technical areas of societal concern and two other areas related to communication of information and ideas. These seven areas were: (1) noise and man; (2) outdoor sound propagation and sources; (3) motor vehicle noise; (4) biomedical acoustics; (5) acoustic applications; (6) interorganizational activities and relationships; and (7) diffusion of knowledge. This paper draws upon the 20-yr-old repository of knowledge to find needs and ideas in the area of noise control that are as relevant today as they were 20 yr ago. The items found in this unfinished agenda provide a partial basis for the development of new initiatives for noise control and insight into the difficulties of their implementation. Hopefully, these ideas and insights can lead to effective execution of new initiatives in the future.

Plumbing Noise and the Classification of Valve Noise

Plumbing noise is a topic often discussed, but despite this fact there still exists a wide range of unknowns related to this particular area of noise control. Research done in Europe and the Scandinavian countries (especially Germany, Denmark, and Sweden) investigated some aspects of the general problem of plumbing noise. As valves are one of the main noise sources in a plumbing system, this subject was investigated first. In addition, valve manufacturers needed some testing method in order to facilitate a redesign of their products with respect to noise. In Germany, work was concentrated on laboratory and field test methods to enable a precise measurement of the plumbing noise. A “noise source” was designed by P. Schneider in Berlin, which enabled relative and absolute measurements. A testing method for the classification of valves developed at the Danish National Institute of Building Research will be discussed in detail. A relative comparison of 13 valves tested under various flow conditions also will be given. In addition, the possibility of classifying a valve by a single number will be discussed.

Control of Noise by Legislation

This area of noise control is illustrated by a consideration of the motor-vehicle noise problem. There is a welter of existing legislation in this country and abroad. It is mostly subjective in nature and therefore generally ineffective in controlling motor-vehicle noise. The objective legislation that does exist is expressed in several different measures, such as dBA, dBB, and dBC, and various measurement distances. Suggestions for objective limits have also included loudness in sones and PNdB. These various limits are compared with one another, with existing and proposed standards, and with limits that appear economically and technically feasible as a result of recent studies. The nature and effectiveness of existing legislation and law enforcement practices are also reviewed.