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1972-02-01
Technical Paper
720639
L. Duthion, C. Doyotte
This paper presents the tracked air cushion vehicle from a noise control point of view. The study, of the different sources of noise, points out that it is possible when using a linear induction motor to reduce the noise level to value as low as possible. In the case of very high speed vehicules other types of propulsion can be used. However it remains possible to reach acceptable noise levels.
1972-02-01
Technical Paper
720640
K. M. Eldred, B. H. Sharp
Horns, whistles and sirens are commonly used to convey information concerning time, location or warning. Of major concern to the community are the audible warning systems used on emergency vehicles and trains. The various types of existing audible warning systems and their historical development are discussed in this paper, together with an analysis of their effectiveness in fulfilling their prime function - namely, to warn people of imminent danger. It is concluded that such systems perform adequately in many situations, but not when the recipient of the warning signal is inside another vehicle. It is suggested that alternative means be developed for warning the occupants of vehicles of immediate danger so that audible warning systems of reduced acoustic power can be used to warn the pedestrian or other persons outside vehicles.
1972-02-01
Technical Paper
720657
Ralph K. Hillquist
Regulation of noise from motor vehicles is an inevitability. To provide optimum benefit to the community at a minimum of additional cost to its citizens, these regulations must recognize the responsibilities of all parties involved, provide uniform requirements as appropriate to the level of government, and embody a flexibility to adapt to new findings and circumstances. Both manufacturer and operator, as regulatees, must be considered in the drafting of vehicle noise restrictions.
1972-02-01
Technical Paper
720658
Kenneth G. Knight
America's need for mass transportation systems to meet the challenge of maintaining urban mobility in the 1970's coincides with a growing public awareness and concern for environmental problems including noise pollution. In rail rapid transit, significant technological advances have already been made and used in modern systems on a voluntary basis to alleviate the effects of operational noise and vibration on both passenger and community. Since quiet costs money, experience has generally proven that enforced legislation is necessary to obtain quieter products from industry. However, the rail rapid transit systems of this country are essential public services which will play an increasingly vital role in urban transportation.
1972-02-01
Technical Paper
720655
A. S. Cooper
Reasonable and effective laws for the enforcement of motor vehicle noise have been enacted and successfully applied in California. Specific laws to prohibit both sale and operation of noisy vehicles were necessary. Measurements by both instruments and human ear judgments are practical and necessary at this time. Noise limits should be gradually reduced commensurate with the needs of the public and the capability of the technology. Future controls on noise producing components, in addition to the complete vehicle, appear to be necessary to obtain desirable minimum levels. California has pioneered interim solutions to portions of this environmental problem and has developed the expertise along with the practical experience to achieve further advancements in solving the problems.
1972-02-01
Technical Paper
720624
Rodger F. Ringham
From various sources of information it is clear that truck noise is a definite public nuisance. Early noise control efforts were very productive in that many heavy duty trucks did not have mufflers, and the addition of this device made clear improvements. Further improvement requires treatment of many sources significant to the overall level. It is felt that today's “tight but attainable” 88 dBA for heavy trucks can reduce to 86 dBA by 1975 and 8k dBA by 1978 with a lot of hard work. There is promise for meaningful noise regulation in the “real world” as indicated by “calibratability” of non-standard sites.
1972-02-01
Technical Paper
720623
Theodore Berland
Trucks are the major source of noise on our streets and highways, affecting the sleep and sanity of millions of city and suburban residents. Truck noise sources are many, but mainly are engine and tires. Since the automotive and trucking industries have not volunteered to quiet truck noises, the Federal government will have to legally require they do so.
1972-02-01
Technical Paper
720621
William B. Becker
United States airlines are deeply concerned about the problem of aircraft noise, and have been actively involved in developing methods of abatement. There are three basic approaches that may be taken to handle this problem: reduction of noise at the source, operational procedures, and control of land use in the vicinity of airports. Aircraft noise is a problem that will be solved only through massive cooperative effort and federal funding. And it should be remembered in any suggested solutions that maintenance of the highest safety standards must be the overriding consideration.
1972-02-01
Technical Paper
720622
Lloyd Hinton
The history of the aircraft noise problem is presented using many references to particularly important studies. Emphasis is placed upon the similarity of expert opinions during twenty years of research for measures needed to resolve the problem. While objectivity is sought -- the common denominator of the aircraft noise issue is controversy -- the author is representing the views of noise impacted airport community residents who cannot comprehend the lack of progress in aircraft noise abatement. This lack of progress has persisted in spite of general agreement on measures needed and is the basis of a call for the reallocation of authority among federal agencies having responsibility both for the regulation of aviation and for the planning and development of urban areas -- including airports -- with environmental protection as basic criterion.
1972-02-01
Technical Paper
720634
Jonathan T. Howe
Laws controlling noise and the role of various local, state and federal agencies must be balanced against their respective interests, limitations of technology and environmental goals. Past attempts to control noise sustain the need for a balanced approach. The interest of obtaining realistic, uniform standards which are enforced by realistic, uniform procedures will advance the cause of noise control. Inconsistent standards and enforcement procedures will only impede effective noise control.
1972-02-01
Technical Paper
720636
P. E. Waters, T. Priede
The paper discusses the fundamental origins of truck noise and shows the rate at which the noise of each individual source increases with speed. Various means of controlling noise from each component are considered. A method of predicting engine noise, and hence vehicle noise, from basic engine speed and piston diameter data is given and the significance of this information to the engine designer is emphasized.
1972-02-01
Technical Paper
720627
Louis H. Mayo
The increasing public concern in recent years over the problem of environmental noise has resulted in the enactment of technology-based regulatory agencies and statutory measures to control technological applications. Most of the earlier controls, however, were reactive measures rather than positive efforts to assure development of a new technology in the public interest. This situation is beginning to change as new environmental codes are being implemented in various states and cities. This paper describes how the noise factor has influenced the planning of transportation systems by various legislative and regulatory entities at the federal, regional, state, and local levels.
1972-02-01
Technical Paper
720625
Robert Alex Baron
Construction noise accompanying the rehabilitation of old and the development of new transportation modes is extremely destructive to the quality of life, and the environment. With few exceptions, industry has failed to internalize the cost of unmuffled equipment and procedures, and the cost of this intense noise exposure is an “external cost” borne by both the worker and the exposed public. Engine equipment manufacturers, contractors, and project sponsors resist design for quiet. Engineers have an ethical imperative to protect the noise receiver. Citizen demand for quieter construction is growing and a few manufacturers are voluntarily marketing quieter compressors and paving breakers. Government, on all levels, is beginning to raise the question of unlimited noise emissions. The Walsh Healey noise exposure limits are now applicable to construction operations.
1972-02-01
Technical Paper
720626
Thomas C. Young
Concern over noise emissions has increased significantly. This paper relates the noise emission problem to other pollution efforts and defines alternative abatement strategies. Major technical and economic parameters are discussed based on the present state-of-the-art. A balanced approach to noise abatement is suggested.
1972-02-01
Technical Paper
720598
Harry Pearson
The paper briefly reviews the evolution of modern aero engines and analyzes the forces which motivate continued technical development, especially the interaction with growth in traffic and aircraft size. The contribution of improved propulsion systems to the economics and regularity of air transport is examined, with particular reference to developments during the past decade. There is some discussion of the environmental factors, particularly noise, raised by civil aviation, the progress already made to deal with them, and the possibilities for the future. The overall benefits of powerplant technical development, particularly as they affect the general and traveling public, are summarized. Examples are drawn from both the United States and European scenes.
1972-02-01
Technical Paper
720615
Albert G. Lucas, George W. Niepoth
The present spark ignition, reciprocating piston, gasoline engine is examined against the basic requirements for an automotive powerplant. The important requirement of emission control is shown to affect these basic requirements. The emission potential of this engine and the prospect of reducing its emissions to an acceptable level are explored. The effect of these factors on future gasoline engines is discussed.
1972-02-01
Technical Paper
720924
T. R. Wik, R. F. Miller
A conceptual framework has been developed for investigating the generation of sound by tires. Recent measurements have quantified some of the characteristics of truck tire sounds. The characteristics that have been measured include the peak A-weighted sound level and its dependence on the tread pattern, speed, and deflection of the tire; the effect of the road surface on tire sound levels; and the spectral distribution of tire sounds. These characteristics are discussed in terms of the mechanisms of tire sound generation.
1972-02-01
Technical Paper
720702
Joseph H. Emme
The noise insulation of operator cabs for construction and agricultural equipment has become increasingly important in the last few years. This paper presents a discussion on the noise control design considerations for the basic structure, control levers, and effective sealing. Also discussed are the parameters to consider in the use of absorption and transmission loss materials.
1972-02-01
Technical Paper
720404
R. H. Lincoln
The current and future regulation of product noise levels required by federal, state, and local authority has been surveyed. Probable effects on product design are presented and discussed, with consideration given to specific problems such as: cost/benefit; enforcement, noise-monitoring networks; lead time; technological feasibility; and design concept changes. All these problems are present and must be considered in any coordinated approach to product noise control.
1972-02-01
Technical Paper
720403
Ralph K. Hillquist
This paper discusses the various vehicle noise test procedures promulgated by SAE, ISO, and ANSI; it notes some shortcomings of these documents and presents suggestions for improving them. The goal is to make these vehicle procedures more representative of typical operating modes and community exposure problems.
1972-02-01
Technical Paper
720406
Lyle F. Yerges
Engine noise control involves well-known methods and procedures, and the methods applied successfully to automotive situations can be applied with equal success to nonautomotive equipment. Three case histories are given in which a problem is solved with existing standard equipment by exerting control at the source, along the transmission path, and to the receiver.
1972-02-01
Technical Paper
720405
Richard D. Strunk
The mechanism of structural noise in internal combustion engines is defined, and its abatement is considered. Structural noise is shown to dominate the other sources of engine noise at high frequencies. The abatement of engine structural noise by employing the fundamentals of isolating high-frequency vibrations, reducing the radiation efficiency of finite panels, and damping resonant vibrations is discussed.
1972-02-01
Technical Paper
720978
Peter G. Masefield
1972-02-01
Technical Paper
720733
Loren E. Lura, Robert B. Walker
Bearing noise may result from variable processing techniques and/or improper application practices. Examples are cited, and methods for measuring bearing sound level are described. It is shown that both the bearing manufacturer and the user have a responsibility in eliminating conditions which may contribute to noisy bearing operation.
1972-02-01
Technical Paper
720697
D. W. Morrison, R. M. Clarke
This paper reports and analyzes two sets of test data that were taken to determine the interior noise levels of typical heavy-duty trucks. Under controlled test conditions, various stationary tests were run in an effort to correlate their results with those obtained during SAE J366 and J336 dynamic tests conducted at the same time. In addition, sound level exposures were determined for various over-the-road operations in an attempt to correlate these results with the static test results.
1972-02-01
Technical Paper
720402
John B. Miller
Acoustic noise has been described as “sound without value.” This paper on acoustic noise is a study of what is called sound, treating of how it is generated, how it is propagated, absorbed, and measured. These specifics are discussed, along with some simple examples of how sound is related to the environment in which it exists.
1971-10-01
Standard
AIR1081
This AIR describes the results of some house noise reduction measurements that were made in five locations in the U.S. in 1966, 1964, 1967, and 1969. The houses used in these tests included a wide range of construction types of single and multiple family dwellings. The house noise reductions also cover a wide range. The average house noise reduction developed in this AIR should be used only when such an average is needed. The principle objective of this AIR is to use these noise reduction measurements to develop curves showing the noise reduction of aircraft flyover noise when the noise passes from the outside to the inside of houses located in various climates. The noise-reduction data presented herein can be applied to measurements of aircraft noise made outdoors in order to estimate the noise levels indoors.
1971-06-01
Standard
J366A_197106
This SAE Standard establishes the test procedure, environment, and instrumentation for determining the maximum exterior sound level for highway motor trucks, truck tractors, and buses. The test results obtained by this test procedure give an objective measure of the maximum noise level emitted by vehicles under a prescribed condition. A subjective rating of the annoyance caused by vehicles in use may not be directly related to this type of noise level measurement.
1971-05-01
Standard
J247_197105
The purpose of this SAE Recommended Practice is to provide guidelines for selection of transducers, data acquisition systems, and other instrumentation as well as analysis methods to help ensure proper measurement and evaluation of acoustic impulses in automobiles. While this Recommended Practice focuses on automotive inflatable devices, such as, frontal airbag systems, pretensioners, inflatable curtains, side airbags, etc, it can be used for measurement of other impulsive sounds in a vehicle if needed. The objective is to achieve uniformity in instrumentation practice and reporting of test measurements. Use of this recommended practice should provide a basis for meaningful comparisons of test results from different sources. This recommended practice specifies procedures for static measurement of acoustic impulses, but due to the much more complicated nature of crash testing, does not specify procedures for measuring impulses in vehicles during crash tests.
1971-04-01
Standard
J919A_197104
This SAE Standard describes the instrumentation and procedures to be used in measuring sound levels at the operator station for self-propelled sweepers as defined in SAE J2130 and self-propelled off-road work machines in categories 1, 2, 4, and 5, of SAE J1116. This SAE document is applicable to machines that have operator stations where the operator can either stand or sit and will be either transported by, or walk with the machine during its operation. The sound levels obtained using this procedure are repeatable and representative of the higher range of sound levels generated by machines under actual field operating conditions. Due to variability of field operating conditions, this data is not intended to be used for operator noise exposure evaluations. Measurement and calculation of the operator's sound exposure should follow SAE J1116.

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