Showing papers on "Noise pollution published in 1994"
TL;DR: Equipment design, modification of nursing care procedures, and increased awareness of noise created by the staff may be effective in reducing noise pollution in these areas.
Abstract: Noise in the operating theatre, recovery room and intensive care unit is above internationally recommended levels. The psychological and physiological effects of noise are reviewed. Equipment and conversation among the staff are major sources of noise in these areas. Equipment design, modification of nursing care procedures, and increased awareness of noise created by the staff may be effective in reducing noise pollution in these areas.
125 citations
TL;DR: In this paper, the question of prediction of sleep disturbance and annoyance due to transportation noise has been addressed and two sets of previously published data have been reanalyzed, and it is concluded that day-night average sound level is still the most adequate noise descriptor for use in environmental impact analyses to assess the annoyance and overall impact of noise from general transportation, including civilian and military aircraft operations.
Abstract: The question of prediction of sleep disturbance and annoyance due to transportation noise has been addressed. Two sets of previously published data have been reanalyzed. This project was initiated as part of a long-term U.S. Air Force research program on the effects of aircraft noise on humans. It is concluded that day-night average sound level is still the most adequate noise descriptor for use in environmental impact analyses to assess the annoyance and overall impact of noise from general transportation, including civilian and military aircraft operations. A new logistic curve adopted in 1992 for general use by U.S. federal agencies, is recommended for use in environmental impact statements as the nominal relationship between day-night average sound level and the percentage of a general residential population predicted to be highly annoyed by the noise. A power curve, using A-weighted sound exposure level, is recommended for predicting nighttime sleep disturbance from general transportation noise.
123 citations
TL;DR: In this article, waveform-recognition techniques were used to detect the presence of simulated cracks in the girders of a laboratory-size bridge as well as a highway bridge.
Abstract: The waveform-recognition techniques introduced in Part I are used to detect the presence of simulated cracks in the girders of a laboratory-size bridge as well as a highway bridge. Bridge structure is excited by using a modal hammer. Vibration response is picked up by using an accelerometer. To study the effect of noise, digital noise is added to the vibration response of the laboratory bridge. The frequency-response function is used as the bridge signature. Each waveform-recognition method described in Part I, except for the cross signature assurance criterion, is used to compare bridge signatures, and the results are evaluated and compared. When no noise is added, all the methods are successful in detecting cracks in the laboratory bridge. When synthetic noise is added, smoothing is used to reduce the noise effect. In the presence of noise, all techniques, with the exception of the equivalent level of degradation system methods, perform well. Using a limited number of signatures from the highway bridge, the waveform chain code is capable of detecting a simulated crack.
61 citations
39 citations
TL;DR: The use of hearing protection devices was associated with lower distress symptoms among the low and moderately annoyed workers, but among the highly annoyed workers the reverse was true and future intervention procedures should focus on unannoyed workers who tend to use hearing Protection devices less.
Abstract: OBJECTIVES--This study tested the hypotheses that, in high noise levels [> or = 85 dB(A)], hearing protection devices are used largely by workers sensitive to noise, as reflected by reports of noise annoyance, and that the usage would reduce distress symptoms. METHODS--Data collected from 1587 healthy male blue-collar workers included noise exposure level, noise annoyance, use of hearing protection devices, distress symptoms (somatic complaints and poststress irritability), and possible confounding by age, education and ethnic origin. RESULTS--Multiple logistic regression results indicated that the use of hearing protection devices was related to noise exposure level [odds ratio (OR) 2.94, 95% confidence interval (95% CI) 2.58--3.30], but more so to high noise annoyance (OR 3.03, 95% CI 2.77--3.29), even after control for age, education, and ethnic origin. No interaction was found between noise level and noise annoyance. These findings highlight the contribution of noise annoyance to the use of hearing protection devices. Of the 42.6% of workers using hearing protection devices in the presence of high ambient noise, 60% were highly annoyed. Noise-annoyed workers also tended to wear hearing protection devices even in low noise levels. The use of hearing protection devices was associated with lower distress symptoms among the low and moderately annoyed workers, but among the highly annoyed workers the reverse was true. CONCLUSIONS--Thus, for the highly annoyed workers, the use of hearing protection devices was perhaps an additional source of stress. One immediate implication of this study is that future intervention procedures should focus on unannoyed workers who tend to use hearing protection devices less.
34 citations
Journal Article•
TL;DR: The role of an acoustic modal description is emphasized in this paper, where wind tunnel tests of model fans and nacelles are described including a novel rotating microphone technique for modal measurement.
Abstract: Results of recent NASA research to reduce aircraft turbofan noise are described. As the bypass ratio of a turbofan engine increases from five to as much as 20, the dominant source of engine noise is the fan. A primary mechanism of tone noise generation is the rotor blade wakes interacting with downstream stator vanes. Methods of analyzing rotor stator tone noise generation are described and sample results are given. The role of an acoustic modal description is emphasized. Wind tunnel tests of model fans and nacelles are described including a novel rotating microphone technique for modal measurement. Sample far field results are given showing the effects of inlet length, and modal measurements are shown which point to a new generation mechanism. Concepts for active fan noise control at the source are addressed. Implications of the research which have general relevance to fan noise generation and control are discussed.
19 citations
TL;DR: In this paper, the authors argue that the fight against traffic noise must not rely solely on the reduction of vehicle-noise-emission levels, but also must include other important actions such as land-use planning, traffic restraints, sound insulation of houses, and highway noise barriers.
Abstract: Vehicle-noise-emission regulations have been effective for more than 20 years in most industrialized countries. The limits for the maximum permissible A-weighted vehicle noise-emission level have been reduced in the order of 9-10 dB in the period from 1970 to 1990. Even with a high international priority on vehicle noise control, we cannot expect a reduction in average traffic noise levels of more than 4 dB by 2010, as a result of vehicle noise legislation alone. Thus the fight against traffic noise must not rely solely on the reduction of vehicle-noise-emission levels, but also must include other important actions such as land-use planning, traffic restraints, sound insulation of houses, and highway noise barriers.
10 citations
14 Sep 1994
TL;DR: In this paper, a bottom-up analysis of the impact of airport noise on residential property values is presented, where the authors make extensive use of local realtors and appraisers who are familiar with the area and any unique factors that must be considered.
Abstract: This report describes the results of a bottom up examination of the impact of airport noise on housing values. The primary objective of this assessment was to determine whether a valid national level determination regarding the impact of airport noise on housing values could be made based on studies at individual airports. The studies were not intended to obtain precise values of the noise impact on property values around the airports that were considered. An analytical approach was designed that combined quantitative techniques in a way that complements each and overcomes some of the shortcomings of previous studies that exclusively used one technique or the other. In recognition of the fact that local conditions can significantly affect real estate markets, this approach makes extensive use of local realtors and appraisers who are familiar with the area and any unique factors that must be considered when assessing the value of residential properties.
10 citations
TL;DR: In this article, two surveys are reported which explore the attitudes of the British public to noise in the countryside and in particular to environmental noise caused by agricultural activities and other uses of farm land.
10 citations
TL;DR: The results reflected that the SPLs in the platforms well exceeded the day time noise exposure limit and the noise dose count of the ticket collector was also in excess of ACGIH standard.
Abstract: To assess the degree of noise pollution in relation to the health and safety of the employees and commuters, a study on the levels of noise originating from various locomotives and also from different other sources was undertaken at Kalupur railway station of Gujarat State in India. The sound pressure levels (SPL) were measured on platforms. Noise dose count was monitored on a ticket collector on duty for 8 h. The results reflected that the SPLs in the platforms well exceeded the day time noise exposure limit. Further, the SPLs produced by loudspeakers were high and those by train whistles were intensely high pitched. The noise dose count of the ticket collector was also in excess of ACGIH standard. All these suggest that the SPLs in the platforms can endanger the healthful living of the users. Suitable control measures have been suggested.
9 citations
Journal Article•
Dissertation•
01 May 1994
TL;DR: Noise reduction is important to protect listeners in high noise environments from hearing damage, to enhance speech communication, and to reduce noise-induced fatigue.
Abstract: : Unwanted noise is a by-product of many industrial processes and systems. In active noise cancellation (ANC), one introduces a secondary noise source to generate an acoustic field that interferes destructively with the unwanted noise, and thereby attenuates it. Noise reduction is important to protect listeners in high noise environments from hearing damage, to enhance speech communication, and to reduce noise-induced fatigue. These adverse effects of noise can cause accidents and reduce the productivity of workers.
Journal Article•
TL;DR: In this paper, three ranking methods were developed to determine the priority of each of the candidate projects, and their application to a set of data from the Chicago area is discussed, and the ranking variables used in developing these procedures are existing noise level, number of people affected, land use type of the adjacent area, and effectiveness and feasibility of building a noise barrier at that location.
Abstract: The ranking of potential noise barrier locations is not a straightforward process and requires consideration of several criteria. The development of multicriteria ranking procedures for prioritizing the locations with noise problems is discussed. Three ranking methods were developed to determine the priority of each of the candidate projects. They are sequential ranking scheme (SRS), analytic hierarchy process (AHP), and weighted index methods. These methods are presented, and their application to a set of data from the Chicago area is discussed. Each of these methods can be used independently by the users. It is proposed that a combination of the SRS and AHP methods be used to improve computational efficiency when a large number of locations are to be ranked. The ranking variables used in developing these procedures are existing noise level, number of people affected, land use type of the adjacent area, and effectiveness and feasibility of building a noise barrier at that location. The ranking variables and their relative importance are the user-specified inputs to these procedures.
Journal Article•
TL;DR: Noise was measured in classrooms of a stratified random sample of 20 schools in Jeddah to reduce transmitted noise by proper city planning, traffic engineering and improved construction characteristics, and to properly select and maintain the air conditioning systems.
Abstract: Noise was measured in classrooms of a stratified random sample of 20 schools in Jeddah. The mean "Average" Leq levels (60-89.2 dB[A]) highly exeed the recommended maximum levels (42-55 db[A]). Noise is higher in the classes adjacent to the streets than in those facing the school courts, particularly at the busy areas, and in the schools of the busy areas than of the semi-busy and of the residential areas. But, noise is lower in the pre-cast structure schools than in the concrete schools due to the better insulating characteristics of the former, and the higher noise induced by the window-type air conditioning units used in the latter. However, the students' recreational activities have equal noise impact in the primary, intermediate and secondary schools. It has been recommended to build schools in low-noise background locations, to reduce transmitted noise by proper city planning, traffic engineering and improved construction characteristics, and to properly select and maintain the air conditioning systems.
Journal Article•
TL;DR: In this paper, a nonlinear association between ground-level noise, altitude, and slant distance was identified, and a combination of altitude, standoff distance, and cruise speed for each helicopter type at which ground level noise is minimum appears to exist.
Abstract: Existing knowledge on helicopter noise focused on the effects of distance and altitude on ground-level noise, the annoyance caused by helicopter noise expressed by people, and the consequences of findings for helicopter operations in rural areas are presented. A nonlinear association between ground-level noise, altitude, and slant distance was identified. A combination of altitude, standoff distance, and cruise speed for each helicopter type at which ground level noise is minimum appears to exist. Also there is a considerable difference between desired and actual noise levels for rural areas even if penalties are not assessed on the measured helicopter noise. A gap in the connection between actual helicopter noise measurements and community annoyance was also revealed. Specific guidelines or regulations that define paths (separation), the frequency of helicopter flights per path, and the minimum standoff distance and altitude may be necessary for semirural and recreational areas
TL;DR: In this article, a laboratory study has been conducted to validate the special procedure recommended by Norwegian authorities for assessing helicopter noise annoyance, and it is recommended that the same procedures for assessing conventional aircraft noise annoyance be used for both fixed wing and rotary wing aircraft without any correction factors.
01 May 1994
TL;DR: The findings were that the percentage of miners surveyed that were subjected to noise exposures above 100%, neglecting personal hearing protectors, were 26.5% and 21.6% for surface and underground mining, respectively.
Abstract: Mine Safety and Health Administration (MSHA) inspectors conduct full-shift environmental noise surveys to determine the occupational noise levels to which coal miners are exposed. These noise surveys are performed to determine compliance with the noise standard promulgated under the Federal Mine Safety and Health Act of 1977. Data from over 60,000 full-shift noise surveys conducted from fiscal year 1986 through 1992 were entered into a computer data base to facilitate analysis. This paper presents the mean and standard deviation of over 60,000 full-shift noise dose measurements for various underground and surface coal mining occupations. Additionally, it compares and contrasts the levels with historical noise exposure measurements for selected coal mining occupations that were published in the 1970`s. The findings were that the percentage of miners surveyed that were subjected to noise exposures above 100%, neglecting personal hearing protectors, were 26.5% and 21.6% for surface and underground mining, respectively. Generally, the trend is that the noise exposures for selected occupations have decreased since the 1970`s.
TL;DR: The findings were that the percentage of miners surveyed that were subjected to noise exposures above 100%, neglecting personal hearing protectors, were 26.5% and 21.6% for surface and underground mining, resp...
Abstract: Mine Safety and Health Administration (MSHA) inspectors conduct full‐shift environmental noise surveys to determine the occupational noise levels to which coal miners are exposed. These noise surveys are performed to determine compliance with the noise standard promulgated under the Federal Mine Safety and Health Act of 1977. Data from over 60 000 full‐shift noise surveys conducted from Fiscal Year 1986 through 1992 were entered into a computer database to facilitate analysis. This paper presents the mean and standard deviation of over 60 000 full‐shift noise dose measurements for various underground and surface coal mining occupations. Additionally, it compares and contrasts the levels with historical noise exposure measurements for selected coal mining occupations that were published in the 1970s. The findings were that the percentage of miners surveyed that were subjected to noise exposures above 100%, neglecting personal hearing protectors, were 26.5% and 21.6% for surface and underground mining, resp...
TL;DR: In this paper, the results of an investigation into the composition of the Dutch car fleet with regard to salient vehicle characteristics such as fuel type, unladen weight and age are discussed.
TL;DR: In this article, the authors developed a computer package for the modelization of environmental noise maps, for Ferrocarriles Vascos, S.A., the Basque rail company, enabling the user to determine the acoustic levels that, under given conditions, will obtain in the vicinity of roads or railways, in fields either free or strongly reverberant, and in urban areas.
TL;DR: The Pilot Project was an initial demonstration which introduced the concept of sound attenuation to residents of homes located between the DNL 65‐ and 75‐dB noise contours, providing four homes with a substantial reduction of interior noise levels due to aircraft noise annoyance.
Abstract: While aircraft noise annoyance does not cause a negative impact on public health, it does affect public welfare. Airports around the country are constantly looking for innovative ways to reduce the impact of airport operations on their neighbors. The Airport’s Residential Sound Attenuation Pilot Project is one of several ways the airport has played an active role in the community, to help improve their neighbors’ quality of life. The Pilot Project was an initial demonstration which introduced the concept of sound attenuation to residents of homes located between the DNL 65‐ and 75‐dB noise contours. Implemented as part of the Airport’s FAR Part 150 Noise Compatibility Program, the Project was designed to provide costing information, design guidelines, and construction methodology for a possible continuing program in which all eligible homes could be sound attenuated. The overall results of the program were extremely successful, providing four homes with a substantial reduction of interior noise levels due to aircraft overflights. The Pilot Project was successful not only as a demonstration of sound attenuation effectiveness, but also as a public relations program in that it showed evidence of the Airport’s commitment to address noise as an issue of importance to the community.
Journal Article•
TL;DR: A variety of health problems accompanied by moderate to high levels of noise is described, which mostly depends on the planner's imagination whether the need for dwelling houses in problem areas could be met in keeping with health demands.
Abstract: While looking for enough living quarters for the town people regional planners are often confronted with high levels of noise due to traffic, highways and railways near the planning area. This may change or even stop the procedure of town planning. Generally, health authorities--who are more or less involved in the process of planning--should take the chance to demand compatibility of special planning with health care regarding noise. However, most guidelines on health-compatible noise levels are not legally binding. This paper describes the variety of health problems accompanied by moderate to high levels of noise. In regions with traffic noise problems efforts should be directed at maximum health compatibility coupled to highly imaginative planning. It is suggested that levels of noise of 55 dB(A) (daytime) and of 45 dB(A) (nighttime) should be tolerated near to the building. This would ensure tolerable levels of noise of 35 dB(A) (daytime) and of 30 dB(A) (nighttime) in the dwellings. Examples of different arrangements of buildings are shown. They demonstrate that these tolerable noise levels could even be observed in areas with traffic problems. It mostly depends on the planner's imagination whether the need for dwelling houses in problem areas could be met in keeping with health demands. Language: de
01 Apr 1994
TL;DR: In this paper, an improved, efficient approach for assessing noise impacts associated with a complex set of noise sources at multiple receptor locations is presented; noise impacts form typical remedial activities at a contaminated industrial site are used as an example.
Abstract: This paper presents an improved, efficient approach for assessing noise impacts associated with a complex set of noise sources at multiple receptor locations; noise impacts form typical remedial activities at a contaminated industrial site are used as an example. The noise sources associated with remedial activities at the site and surrounding areas are described, the noise-propagation modeling methods and results are presented, and an impact assessment of the contaminated site is discussed with regard to applicable regulatory standards and individual and community responses. Also discussed is the improved noise assessment approach. The improved features demonstrated are automate approaches for (1) inputting long-term hourly meterorological data (e.g., 8,760 hours for a one-year period) into a long-range noise-propagation model for computing noise-level increases at receptor locations and (2) analyzing potential individual and community responses to intrusive noises using the IAP and modified CNR.
01 Jun 1994
TL;DR: In this paper, a brief overview of computer programs currently available (operational) for predicting the effects of such meteorological conditions on audible noise levels in a format that allows gross comparison of the relative capabilities of the programs from the standpoint of engineering application to environmental impact assessment.
Abstract: Assessment of the environmental impacts of audible noise produced by human activities -- such as construction and operation of industrial facilities, vehicular traffic, and aircraft operations -- requires the use of sound-propagation computer programs capable of predicting the sound-pressure spectra that will be produced by these noise sources at distances as great as 10 km. Under acoustically unfavorable meteorological conditions, such as ground-based temperature inversions and noise-sensitive receptors being located downwind from intrusive sound sources, audible noise levels can be increased, even on the order of 20 dB. This paper presents a brief overview of computer programs currently available (``operational``) for predicting the effects of such meteorological conditions on audible noise levels in a format that allows gross comparison of the relative capabilities of the programs from the standpoint of engineering application to environmental impact assessment.
31 Dec 1994
TL;DR: In this paper, the Westinghouse Acoustic Model (WAM) was used for power project noise prediction and has been benchmarked against field test data, showing that WAM can be successfully incorporated by early consideration of siting issues and by utilization of proven design and analysis techniques.
Abstract: Environmental requirements for power generation projects are becoming more stringent every year. Acoustical criteria are also becoming a more important issue since facilities are being located closer to residential areas. In response, industry has developed advanced low noise designs which minimize the impact on the environment and on public welfare. When predicting the sound levels resulting from operation of a project, careful attention must be given to siting considerations, such as background ambient sound levels, proximity to sensitive receptors, terrain, general arrangement of equipment, and atmospheric conditions. Successful design strategies and analysis techniques have been developed, as demonstrated by a comparison of predicted sound levels with actual data from operating combustion turbine projects. A critical element in the design and analysis of these projects was the utilization of the Westinghouse Acoustic Model (WAM) computer program. WAM was developed specifically for power project noise predictions and has been benchmarked against field test data. Appropriate noise control features can be successfully incorporated by early consideration of siting issues and by utilization of proven design and analysis techniques. These techniques are also useful to minimize impacts on project thermal performance, cost, and general arrangement of equipment. Examples and guidelines are provided.
TL;DR: In this paper, the authors collected noise exposure data (n≳150 samples) during normal commercial air travel, using noise dosimeters, and an octave-band analyzer, and the resulting noise exposures for air passengers were presented, including the distribution of measured A-weighted sound pressure levels.
Abstract: Over a period of several years the authors have collected noise exposure data (N≳150 samples) during normal commercial air travel. The data were collected utilizing noise dosimeters, and an octave‐band analyzer. The resulting noise exposures for air passengers will be presented, including the distribution of the measured A‐weighted sound pressure levels. In addition, as part of regular class assignments, the students of the first author’s Effects Of Noise And Vibration graduate class have collected sound exposure data over several years at popular bars, restaurants, discos, and socialization establishments in the Raleigh, NC area. The noise exposures and sound level distributions from these surveys will also be presented.
Journal Article•
TL;DR: A random sample of 1000 citizens in the City of Erfurt, who were written to and personally interviewed, also having their exposure to noise emissions measured enabled a quantitative estimate to be made of the level of noise pollution to which the population was subjected.
Abstract: The Reference Laboratory for Local Noise Protection in the former German Democratic Republic selected a random sample of 1000 citizens in the City of Erfurt, who were written to and personally interviewed, also having their exposure to noise emissions measured. This enabled a quantitative estimate to be made of the level of noise pollution to which the population was subjected, while simultaneously contributing towards determining an annovance threshold and demonstrating the important role played by subject-specific factors in any one person's perception of the annoyance caused by noise. However, it proved impossible to develop any universal, objective procedure which at the same time would be practicable and would correctly assess all types of noise in terms of the effects they generate.
Journal Article•
TL;DR: In this article, an airport ground-noise abatement study was conducted for the Port Authority of New York and New Jersey along the western boundary of La Guardia Airport between 1986 and 1988.
Abstract: An airport ground-noise abatement study was conducted for the Port Authority of New York and New Jersey along the western boundary of New York City's La Guardia Airport between 1986 and 1988. The investigation included measurements to characterize multiple noise sources, analysis of noise abatement options, and postconstruction measurements. The noise barrier design was conducted by using one-third-octave band analysis to predict expected loss of excess ground attenuation, barrier insertion loss, and net noise reduction. The study used the DIFRCT model developed by Embleton, Piercy, and Isei to calculate noise barrier insertion losses in the presence of ground effects. Although an example of one particular application and not a thorough review of the model is provided, the following conclusions were noted. The modified DIFRCT model was useful in predicting the ground effect owing to soft ground, especially at lower frequencies. In addition the study indicated that the model may be limited in its applications to hard-ground situations because of lack of coherent long-distance propagation at higher frequencies.