Showing papers on "Noise pollution published in 1981"

Direct comparison of community response to road traffic noise and to aircraft noise

Abstract: Previous efforts to synthesize information on community responses to various noise sources have been forced to rely on a variety of surveys conducted in different countries over a number of years. Comparability of both the noise measurements and the questions asked has been limited, and has of necessity relied on professional judgment. Data collected recently around Toronto International Airport provide a direct comparison of response to two sources, based on 673 interviews of persons exposed to a variety of levels of both aircraft and road traffic noise. The results of that analysis do not support the assumption that response to these two noise sources is the same. For the same value of Ldn, a greater percentage of the sample is highly annoyed by aircraft noise than by road traffic noise. Possible reasons for this contradiction of the results of a previous synthesis of noise surveys are discussed.

Occupation related fire fighter hearing loss

Abstract: A noise exposure survey and audiometric assessment of 750 Los Angeles City fire fighters carried out to study the impact of fire service noise exposure on fire fighter hearing loss revealed evidence of excess hearing loss at the 3000 Hz, 4000 Hz, and 6000 Hz test frequencies. Fire fighter medical history and life-style data did not point to a significant impact of hobbies and diseases on hearing threshold changes. The hearing loss observed at the test frequencies was, in relation to age, in excess of a general national population. This increased hearing loss with age for fire fighters suggests occupational overexposure to noise. A hearing conservation program for the fire service is therefore recommended.

Community noise levels in Patras, Greece

Abstract: In the city of Patras (Greece), noise measurements were made for the purposes of determining the present noise-pollution levels and the reaction of the people to them. For the latter purpose, a social survey was conducted with the use of a relevant questionnaire which was applied to 500 citizens. Its results show that noise pollution is ranked second in order after air pollution, and that traffic was the principal noise pollutant. The mean noise levels, in 25 monitoring stations throughout the city, were found to be high and definitely unacceptable. For three representative locations, corresponding to high, medium, and low traffic volume, the various statistical noise descriptors, such as Leq, LNP Ldn and others, were used, together with the other measurements, to estimate the noise environment of the entire city. The high degree of annoyance of the people is justified by the high values of Leq, LNP, Ldn, and TNI that were found.

Annoyance by aircraft noise and fear of overflying aircraft in relation to attitudes toward the environment and community.

Abstract: If, as has been suggested, expressions of annoyance attributable to aircraft noise may reflect, in part, fear of aircraft overflights and possible crashes, then residents of areas where crashes have occurred should express more annoyance. To test this hypothesis, 50 residents of an Albany, New York area where an aircraft crash producing fatalities recently occurred, and 50 residents of a comparable nearby area without such a history, were asked to respond to a "Quality of Life" questionnaire. Among the items were some designed to test annoyance by noise and fear of aircraft overflights. It was predicted that those in the crash area would express more fear and would more often identify aircraft as a noise source. Factor analysis and discriminant analysis results sustained these hypotheses. A near-replication was carried out in Louisville, Kentucky; results were much the same. For the crash-area groups there was association of aircraft fear and noise annoyance responses; this was true to an apparently lesser extent for non-crash-area groups. The greater annoyance of crash groups by aircraft community noise apparently does not carry over to assessment of aircraft noise in the laboratory. Language: en

Highway noise, noise mitigation, and residential property values

Abstract: This paper presents the findings of a study of the relationship between different noise levels and market values for a sample of 206 single-family residences abutting Interstate-495 in Northern Virginia and for a sample of 207 residences along two heavily traveled urban streets in the Tidewater area of Virginia. Estimates of the influence of noise on the market price of houses sold in 1978-1979 at these sites, where barriers have since been completed, were then used to estimate economic benefits received by property owners. By using these estimates, it was concluded that recent public expenditures on highway noise abatement per household far exceed reasonable economic benefit levels, even for noise reductions of 10 dB(A). (Author)

Noise in the mining industry. An overview

Abstract: This paper surveys noise levels, noise exposure patterns, and frequency spectra found in the mining environment; the effects of mining noise on the working population; and the quantification of hearing loss in the coal mining industry. Federal mining noise regulations and the present state of the industry, with respect to noise control technology, are discussed. Examples of proven noise controls for mining are included along with measured noise reductions.

Occupational noise exposure and hearing levels

Abstract: A study was made at the Bhabha Atomic Research Center to measure the hearing levels of persons working in a noisy environment. Two different workplaces, central air-conditioning plant and glass blowing shops, where a number of persons were exposed to noise levels exceeding 85 dB(A) were chosen. The occupational exposure to noise was determined using a sound level meter, an octave band filter and a personal noise dose meter. The hearing levels of persons exposed to these high levels of noise and a control group not exposed to occupational noise were measured by means of a pure-tone audiometer in a specially-built booth. These persons, aged between 20 to 60 years, were divided into four age groups for the study. The low ambient noise levels in the booth were measured using correlation technique since such low signals cannot be detected by an ordinary sound level meter. The audiometric findings and the results of the noise level survey are discussed in this paper.

Measured and calculated characteristics of wind turbine noise

Abstract: The results of an analytical and experimental investigation of wind turbine noise are presented Noise calculations indicate that for configurations with the rotor downwind of the support tower, the primary source of noise is the rapid change in rotor loadings which occurs as the rotor passes through the tower wake Noise measurements are presented for solid and truss type tower models with both upwind and downwind rotors Upwind rotor configurations are shown to be significantly quieter than downwind configurations The model data suggest that averaged noise measurements and noise calculations based on averaged tower wake characteristics may not accurately represent the impulsive noise characteristics of downwind rotor configurations

GE MOD-1 noise study

Abstract: Noise studies of the MOD-1 Wind Turbine Generator are summarized, and a simple mathematical noise is presented which is adequate to correlate the sound levels found near the machine. A simple acoustic measure is suggested for use in evaluating far field sound levels. Use of this measure as input to a currently available sound complaint prediction program is discussed. Results of a recent statistical survey relative to the far field variation of this acoustic measure because of atmospheric effects are described.

Resident annoyance response to aircraft noise events

Abstract: In a study conducted in the vicinity of Salt Lake City International Airport, community residents reported their annoyance with individual aircraft flyovers during rating sessions conducted in their homes. Annoyance ratings were obtained at different times of the day. Aircraft noise levels were measured, and other characteristics of the aircraft were noted by trained observers. Metrics commonly used for assessing aircraft noise were compared, but none performed significantly better than A-weighted sound pressure level. A significant difference was found between the ratings of commercial jet aircraft and general aviation propeller aircraft, with the latter being judged less annoying. After the effects of noise level were accounted for, no significant differences were found between the ratings of landings and takeoffs. Aircraft noise annoyance reactions are stronger in lowered ambient noise conditions. This is consistent with the theory that reduced nighttime and evening ambient levels could create different reactions at different times of day. After controlling for ambient noise in a multiple regression analysis, no significant differences were found between the ratings of single events obtained during the three time periods: morning, afternoon, and evenings.

Minimum noise impact aircraft trajectories

Abstract: Numerical optimization is used to compute the optimum flight paths, based upon a parametric form that implicitly includes some of the problem restrictions. The other constraints are formulated as penalties in the cost function. Various aircraft on multiple trajectores (landing and takeoff) can be considered. The modular design employed allows for the substitution of alternate models of the population distribution, aircraft noise, flight paths, and annoyance, or for the addition of other features (e.g., fuel consumption) in the cost function. A reduction in the required amount of searching over local minima was achieved through use of the presence of statistical lateral dispersion in the flight paths.

An Investigation of the Mechanics and Noise Associated with Coal Cutting

Abstract: The results of the a laboratory investigation of coal cutting mechanics and noise are presented. These experiments were performed using a linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts was ascertained. Theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to formulate analytical models of the coal cutting forces and noise. The analytical model for coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator's position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise as well as provide benefits to other important areas of health and safety in underground mining. 16 refs.

Community Reaction to Impulse Noise: Initial Army Survey.

Abstract: : This report gives the results of a noise-impact attitudinal survey done in the Fort Bragg/Fayetteville, NC, area. It shows that to the extent normal sources like airplanes fit an energy model (such as the day/night average sound level (DNL), impulse noise also fits an energy model. The growth of annoyance levels in a community with increases of loudness occurs similarly for impulse noise and for aircraft and helicopters. The growth of annoyance in a community with increases in the frequency of occurrence of events occurs in a similar way for all noises, except that the integration period for impulse noise apparently extends down to 'once every few months,' whereas annoyance all but dies away for other noises when the frequency of occurrence drops this low. All types of noise sources have roughly the same nighttime noise penalty -- 7 to 10 dB. C-weighting is the best available standard measure; a C-weighted DNL (CDNL) which includes no threshold or impulse correction factor offers the best model to describe community response. To establish an equivalency between CDNL levels used to assess impulse noise and A-weighted DNL (ADNL) levels used to assess other noise, it is necessary to find a common denominator. It is recommended that the percent of the community 'highly annoyed' in a given noise climate be that common denominator. With this common denominator, about 6 dB must be added to the numerical value of the CDNL level. (Author)

The noise exposure of operators of mobile machines in U. S. surface coal mines, 1979. Information circular

Abstract: This report, summarizing the results of two studies sponsored by the Bureau of Mines, presents information on the types of mobile machines used in surface coal mines in the United States, and the amount of noise to which miners are exposed. Data consist of a calculated value of the probability of noise overexposure, caused by specific equipment. These data are extrapolated to estimate the number of overexposed operators. Bulldozers were identified as the major contributors to noise overexposure, and the report presents results of a Bureau-funded program on the feasibility of providing retrofit noise control on bulldozers.

Blast Noise Prediction. Volume I. Data Bases and Computational Procedures.

Abstract: : Over the past several years, the Construction Engineering Research Laboratory has gathered data from various sources dealing with blast noise generation and propagation and has performed several sets of field measurements designed to enhance this data base. These studies have been performed as a part of efforts aimed at improving methods of predicting the noise impact of military installations. Specifically included are measurements of the directivity pattern of major Army weapons and the statistical propagation and blast noise in the atmosphere. Volume I of this report develops and explains the relations among the various data bases which have been developed to predict blast noise impact of Army facilities. From these studies, data bases and computational procedures which are used within the Blast Noise Prediction computer program (BNOISE 3.2) are developed.

On the correlation between objective measurements and subjectively felt disturbance from traffic

Abstract: Measurements of traffic noise during the day were taken at 90 measurement points over the urban area of Vienna; in addition, the vehicle frequency ascertained at the individual measurement points was also noted. Results of these objective measurements or various characteristic single values derived from them are compared with the results of the environmental survey of 1973 on the subjective noise stress experienced within buildings but caused by outside factors. Suggestions for suitable measures to describe the traffic noise and to derive limit values are given considering the relationship between number of vehicles and noise and annoyance.

Noise generation of upwind motor wind turbine generators

Abstract: Noise sources of wind turbines with rotors upstream of the support structure are discussed along with methodology for sound level prediction. Estimated noise levels for the MOD-2 wind turbine are presented operating in both the upwind and downwind configurations. Results indicate that upwind rotor configurations may be advantageous from an acoustical standpoint.

Blast Noise Prediction. Volume II. BNOISE 3.2 Computer Program Description and Program Listing.

Abstract: : Over the past several years, the Construction Engineering Research Laboratory has gathered data from various sources dealing with blast noise generation and propagation and has performed several sets of field measurements designed to enhance this data base. These studies have been performed as a part of efforts aimed at improving methods of predicting the noise impact of military installations. Specifically included are measurements of the directivity pattern of major Army weapons and the statistical propagation of blast noise in the atmosphere. User instructions and a system description for Blast Noise Prediction computer program, BNOISE 3.2 are given in Volume II. Also included is the procedure for using the program to obtain a noise contour for a specific set of data; how subroutines are invoked in a modular fashion; a description of module functions; module calling procedure; algorithms used by the program; and a summary of error messages.

The effect of airplane noise on the inhabitants of areas near Okecie Airport in warsaw

Abstract: The state of health and noise annoyance among persons living in areas near Okecie airport exposed to various intensities of noise was evaluated. Very high annoyance effects of airplane noise of intensities over 100 dB (A) were established. A connection between the airplane noise and certain ailments complained about by the inhabitants was demonstrated.

A three-dimensional geometrical noise model for traffic noise simulation

Abstract: In this paper, a three-dimensional geometrical noise model for single vehicles on a freeway is described. Its derivation is based on the propagation of sound energy from a point source in a free field. It is then generalized to all type of road vehicles by including in it between-type and within-type variations. The temporal characteristics of traffic noise is simulated using a digital computer from which statistical information is derived and traffic noise indices such as mean noise level, peak noise level, background noise level, noise pollution level, and equivalent steady noise level are evaluated. Close agreement was obtained between the predicted values and the measured values in five separate assessments of the model using freeways of three different speed limits in the state of New South Wales, Australia.

Effects of aircraft noise on the equilibrium of airport residents: testing and utilization of a new methodology

Abstract: The focus of the investigation is centered around two main themes: an analysis of the effects of aircraft noise on the psychological and physiological equilibrium of airport residents; and an analysis of the sources of variability of sensitivity to noise. The methodology used is presented. Nine statistical tables are included, along with a set of conclusions.

Effects of aircraft noise on the equilibrium of airport residents: Supplementary analyses to the study carried out around Orly

Abstract: The effects of aircraft noise on humans living near airports were studied. Two main questions were considered: do residents give evidence of psychological or physiological disturbances in unusually intense noise sectors; and do personality or health factors account for the high interindividual variability of annoyance? The methodology used and results obtained are presented. Samples of the survey questionnaires are included.

Nature of the annoyance and noise annoyance relation around airports

Abstract: A survey of 5,000 individuals living around Orly Airport is described. The psobic index was used as the noise index which indicated the intensity of the annoyance experienced by people living around the airport. The results indicate that sensitivity to noise is related to certain personal factors.

Indoor noise level limits for residential areas affected by transportation noise

Abstract: Noise criteria for buildings are often set on the basis of expected annoyance levels, which in turn may be seen as a function of activity interference, particularly speech or sleep disturbance The relationships between various physical measures of noise, reported activity interference, annoyance due directly to the activity interference, and overall annoyance are as yet not clear This paper describes a probabilistic model linking these variables, and presents a preliminary test of the model using a small data set Houses exposed to road traffic noise and aircraft noise were chosen At each house, detailed noise measurements were taken simultaneously outside and inside the house, using two real time one‐third octave band analyzers In addition, a member of the household was asked about activity interference around the house, and about overall annoyance These data permit feasibility tests of the model, which will later be tested on a more extensive data set If successful, the model will help to identify acoustical insulation requirements for different noise environments, as well as permitting identification of those aspects of outdoor noise which lead to indoor speech interference and annoyance This in turn is essential information for setting indoor noise criteria

Comparison of predicted engine core noise with proposed FAA helicopter noise certification requirements

Abstract: Calculated engine core noise levels, based on NASA-Lewis prediction procedures, for five representative helicopter engines are compared with measured total helicopter noise levels and proposed FAA helicopter noise certification requirements. Comparisons are made for level flyover and approach procedures. The measured noise levels are generally significantly greater than those predicted for the core noise levels, except for Sikorsky S-61 and S-64 helicopters. However, the predicted engine core noise levels are generally at or within 3 db of the proposed FAA noise rules. Consequently, helicopter engine core noise can be a significant contributor to the overall helicopter noise signature and, at this time, will provide a limiting floor to a further decrease in future noise regulations.