Showing papers on "Noise pollution published in 1991"

Noise exposure from leisure activities : a review

Abstract: Over the past two decades there has been increasing concern about the role of nonoccupational, or leisure noise on hearing. This paper reviews published studies that detail the noise levels and potential effects of some noisy leisure activities. Considered are the most common sources of leisure noise: exposure to live or amplified rock, classical, or jazz music; exposures from personal listening devices (‘‘walkman’’ type); noise around the home, and hunting and target shooting. Although all activities listed above have the potential for dangerous levels of noise exposure, the most serious threat to hearing comes from recreational hunting or target shooting.

Aeroacoustics of large wind turbines

Abstract: This paper reviews published information on aerodynamically generated noise from large horizontal axis wind turbines operated for electric power generation. Methods are presented for predicting both the discrete frequency rotational noise components and the broadband noise components, and results are compared with measurements. Refraction effects that result in the formation of high-frequency shadow zones in the upwind direction and channeling effects for the low frequencies in the downwind direction are illustrated. Special topics such as distributed source effects in prediction and the role of building dynamics in perception are also included.

A review of the non-auditory effects of noise on health

Abstract: This paper reviews epidemiological studies, human experimental studies, and animal research on the non-auditory effects of noise on health. The following topics are covered: vegetative responses (e.g., blood pressure, digestion), biochemical effects, excretion of catecholamines, sleep, physical illness, subjective annoyance, and mental health. Combined effects of noise and other occupational health hazards on physiological functioning and health are also reviewed. Overall, the results suggest that there are non-auditory health effects. However, these require confirmation in prospective, longitudinal studies with interventions reducing noise levels.

The annoyance caused by simultaneous noise and vibration from railways

Abstract: A study has been conducted to determine a method of predicting subjective response to simultaneous noise and vibration produced in buildings near railways. The method of magnitude estimation was used by 20 subjects to indicate the annoyance produced by vibration and noise in houses during the passage of six trains. The subjects were exposed to 90 stimuli consisting of 15 paired combinations of four levels of noise and four magnitudes of vibration for each of the six trains. The influence of duration, magnitude, and frequency of vibration and the effect of simultaneous noise were combined to provide a method of predicting the relative annoyance for different combinations of noise and vibration. The resulting relation, which involved the summation of the individual effects of the two stimuli in terms of the vibration dose value and the sound exposure level, was shown to provide a more accurate means of predicting the overall reaction from simultaneous noise and vibration than a method based on either noise or vibration alone. It may also be employed to indicate the relative importance of the two stimuli. The findings suggest that the vibration dose value and the sound exposure level are sufficient to provide useful approximations to subjective reactions to short duration exposures to railway vibration and noise.

Noise annoyance during the performance of different nonauditory tasks.

Abstract: Three experiments were performed to study the effects of an ongoing task on the annoyance response to noise. In the first two experiments a total of five tasks were used: three versions of a proofreading task, a finger-dexterity task, and a complex reaction time (RT) task. Subjects performed the tasks during exposure to two levels of a continuous broadband noise. Task was of no consequence for rated annoyance. Four tasks were used in Experiment 3: proofreading, complex RT, grammatical reasoning, and simple RT. A third type of noise, irrelevant speech, was added to the broadband noises. Rated annoyance was lower during simple RT than during the reasoning and proofreading tasks, especially in the irrelevant speech condition. The difference corresponded to a 6-dB difference in noise level. It was concluded that task differences probably only explain a small part of the widely differing noise tolerance levels at different work places.

Modeling the interactions between noise exposure and other variables.

Abstract: The interaction of noise exposure with other variables is reviewed. For the case of the interaction of noise with other variables that produce behavioral threshold shifts, the application of a newly developed model is described and demonstrated. This model, referred to as the modified power‐law model, provides an accurate prediction of the combined effects of two threshold‐elevating factors. The model accounts for the interaction of post‐exposure threshold shift with pre‐exposure hearing loss, whether the hearing loss was a pre‐existing permanent loss or a pre‐existing temporary loss. The model’s application is demonstrated for multiple exposures to steady‐state noise in which each exposure lasts as short as 12 min or as long as 6 h. Finally, implications of the model’s application to the interaction of noise with other ototraumatic agents are reviewed.

The noise hazard in a large health care facility.

Abstract: A noise-level survey, dosimetry, and audiometric testing were conducted in a large health care facility to determine the areas with hazardous noise levels, the number of employees at risk, and the prevalence of noise-induced hearing loss (NIHL) among the exposed. Nine high-risk areas were identified, with readings of up to 110 dBA recorded. In the work force of approximately 6,000 employees, 321 were identified as exposed to potentially hazardous noise levels. Abnormal hearing patterns were observed in 59 (19%) of the 308 workers screened, with 36 cases of NIHL documented. The findings showed that noise is a serious hazard in many areas, that some cases of NIHL have developed from occupational exposure in this hospital, and that a control program is essential.

Cardiovascular responses and electroencephalogram disturbances to intermittent noises: effects of nocturnal heat and daytime exposure.

Abstract: During sleep, in thermoneutral conditions, the noise of a passing vehicle induces a biphasic cardiac response, a transient peripheral vasoconstriction and sleep disturbances. The present study was performed to determine whether or not the physiological responses were modified in a hot environment or after daytime exposure to both heat and noise. Eight young men were exposed to a nocturnal thermoneutral (20 degrees C) or hot (35 degrees C) environment disturbed by traffic noise. During the night, the peak intensities were of 71 dB(A) for trucks, 67 dB(A) for motorbikes and 64 dB(A) for cars. The background noise level (pink noise) was set at 30 dB(A). The noises were randomly distributed at a rate of 9.h-1. Nights were equally preceded by daytime exposure to combined heat and noise or to no disturbance. During the day, the noises as well as the background noise levels were increased by 15 dB(A) and the rate was 48.h-1. Electroencephalogram (EEG) measures of sleep, electrocardiograms and finger pulse amplitudes were continuously recorded. Regardless of the day condition, when compared with undisturbed nights, the nocturnal increase in the level of heart rate induced by heat exposure disappeared when noise was added. Percentages, delays, magnitudes and costs of cardiac and vascular responses as well as EEG events such as transient activation phases (TAP) due to noise were not affected by nocturnal thermal load or by the preceding daytime exposure to disturbances.(ABSTRACT TRUNCATED AT 250 WORDS)

An assessment of the effect of residential acoustic insulation on prevalence of annoyance in an airport community

Abstract: A social survey was undertaken to compare the prevalence of noise‐induced annoyance in two residential populations with similar aircraft noise exposure in the vicinity of Hartsfield International Airport (ATL) in Atlanta, Georgia. One population was composed of residents of homes that had been treated to increase their acoustic transmission loss. The other population was composed of residents of homes that had not been so treated. No clear benefit of home noise insulation was observed in terms of lowered prevalence of annoyance to aircraft noise exposure.

Effects of peak pressure and energy of impulses.

Abstract: Peak pressure has been one of the key parameters of impulse noise used to assess the hazard to hearing. It is used in most international noise exposure limits. France uses an A‐weighted energy limit. There is a rough correspondence between peak pressure and the hazard to hearing for a given type of impulse noise. However, when the effects of different types of impulses are compared, this correspondence breaks down. One of the alternate measures of impulse intensity is weighted energy. Weighted energy is appealing for a number of reasons. It does not depend on details of the pressure‐time history such as the peak pressure and the more common duration measures. It should be easier to integrate with continuous or intermittent noise standards. It would make it easier to use standard hearing protector attenuation to estimate the hazard when a specific hearing protector is worn. Results of previously published articles and reports will be discussed. These reports lead to the conclusion that weighted energy is a more potent determiner of hearing hazard than peak pressure if spectral effects are controlled.

An updated catalog of 318 social surveys of residents' reactions to environmental noise (1943-1989)

Abstract: All social surveys of residents' reactions to environmental noise in residential areas which were described in English language publications from 1943 to 1989 are identified. A total of 318 surveys are described. The surveys are indexed by country, noise source, and data of survey. The publications and reports from each survey are listed in a bibliography. Twenty-four surveys are listed which are available for secondary analysis from a data archive.

Proceedings of noise-con 91

Abstract: This volume covers the following topics related to noise control: control of mine ventilation fans; physical phenomena; gas turbine exhaust system silencing; computer models for estimating electric utility environmental noise; noise from rotary coal car unloading; noise analysis.

Flyover-noise measurement and prediction

Abstract: Details are presented for the measurement and prediction of aircraft flyover noise to be used for certification, research and development, community noise surveys, airport monitors, and pass fail criteria. Test details presented are applicable to all types of aircraft, both large and small, and the use of Federal Aviation Regulations (FAR) Part 36 (ref. 1) is emphasized. Accuracy of noise measurements is important. Thus, a pass-fail criterion should be used for all noise measurements. Finally, factors which influence the sound propagation and noise prediction procedures, such as atmospheric and ground effects, are also presented.

Study of noise pollution in Jeddah hospitals.

Abstract: The present study was conducted on a sample of 6 hospitals in Jeddah to investigate the status of noise pollution there, and as related to community background noise, operational activities, hospital size and operational concepts (public vs private). Generally, the levels of noise in the clinics, patient rooms, offices, waiting areas and corridors significantly exceed the recommended standard. The noise levels in the machinery rooms significantly exceed the levels in offices, waiting areas and corridors which, in turn, significantly exceed the levels in clinics and patient rooms. Background community noise has a little impact on indoor noise due to the construction characteristics of the hospitals' buildings. However, "operational noise" from machinery and from the move of public (patients, attendants and employees) significantly contribute to indoor noise. Proper site location, city planning, traffic engineering, building construction, equipment selection, construction and equipment maintenance, and system management have been recommended for the abatement of hospital noise pollution.

Development of a new noise Helmet

Abstract: A prototype for a new noise helmet was developed because high noise levels were not sufficiently attenuated by commercially available helmets The new helmet was designed to be tight, especially in the area of the throat and face, and to cover the entire head The noise attenuation properties of the new helmet were tested against pink noise in an anechoic room, jet engine noise, and low-frequency noise with the test subjects wearing a miniature microphone under the protector The new helmet provides insertion loss of over 50 dB, which is 18–29 dB more attenuation than that of the tested earmuffs in the frequency range of 1–8 kHz It is also better (8–13 dB) than the tested earmuffs at frequencies of 125–1000 Hz, and it protects against air impurities because the air fed into the helmet is filtered

Modeling Lateral Attenuation of Aircraft Flight Noise

Abstract: : Airbase and/or airport noise prediction models such as the Air Force NOISEMAP computer program are used to forecast the long term noise exposure from aircraft flight and ground activity at a facility. Noise contour maps from these calculations are used to assess the potential adverse effects such noise may have on the environment and to assist nearby communities in performing compatible land use planning. To calculate the noise exposure at any specified ground position located to the side of a flight path, a variety of noise attenuation mechanisms must be accounted for if the model is to predict levels that are in reasonable agreement with field noise measurements. For such locations, the attenuation effects are usually grouped as being due to: (1) wave divergence (spherical spreading), (2) atmospheric absorption, and (3) lateral attenuation, (the combined attenuation due to ground, meterological, forward flight, and engine/airplane installation effects).

The combined effects of noise, nightwork and meals on mood.

Abstract: The present paper descirbes a laboratory study on the acute effects of a combination of noise and nightwork on subjective mood. Subjects tested in the presence of noise felt more alert than those tested under quiet conditions. Circadian variation in alertness was also reported, but the noise did not change the shape of the alertness rhythms. The only exception to this was found after the mid-shift meal. Subjects tested under quiet conditions felt less alert after the meal than before it, whereas those tested in the presence of noise reported that they were more alert in the post-meal period. These results suggest that noise and nightwork produce independent effects, whereas noise and meals influence similar mechanisms.

An acoustic map of a district in the city of Valencia

Abstract: Of the numerous factors contributing to environmental pollution, noise is one of the most common and important. Acoustic contamination is currently considered a serious threat to the quality of life in the industrialized world. An acoustic map was produced to study the effect of environmental noise on the inhabitants of the neighbourhood of Natzaret, in Valencia (Spain). On analyzing the sources of noise, the high percentage of points (37%) where the passing of heavy load vehicles was reported should be pointed out, together with the presence of industrial noise at 28% of the points. As to the hourly variations in noise levels, a 20 dB A difference was observed between day‐ and night‐time levels; contrary to the usual results in this type of recordings, no decrease in noise levels was observed over the weekend.

Chapter 9 Noise Pollution

Abstract: Publisher Summary This chapter focuses on noise pollution. Early awareness of the need for noise control and of the options for noise control lead to measures that have lasting and widespread effectiveness rather than being remedial and local in their impact. The chapter reviews basic descriptions of sound and subjective response to sound and outlines the methods of assessing traffic noise impact in the community. The sources of traffic noise are discussed and methods of control at source are given. Methods of measuring and monitoring traffic noise and highway-induced vibrations are described. Factors to be considered in forecasting the propagation of sound outdoors and in prediction schemes for noise both from free flowing traffic and from stop–start traffic are introduced. The methods of traffic noise control are detailed. There are three possible approaches to control the impact of traffic noise: reduction at source involves the design of quieter vehicles and road surfaces; control between source and receiver; and control at the receiver.

A Study of Home Science Teachers' Perceptions of Domestic Environmental Pollution in Limuru Division Primary Schools, Kiambu District

Abstract: This study aimed at investigating primary Home Science teachers' perceptions of domestic environmental pollution. The area under study was Limuru Division, Kiambu District. In particular, the study sought to establish whether or not Home Science teachers considered the home as an important source of pollution. In addition, the study sought to establish whether the teachers had basic knowledge and understanding of various aspects of household pollution. Another aim was to find out whether their perceptions of domestic pollution influenced their teaching.The research was a simple survey and its sample was made up of 38 teachers who teach Home Science in the selected schools. Data was collected using questionnaires and analysed using simple descriptive statistics and percentages. The results of the study revealed the following: 1) Although about a half of the teachers considered the home as an important source of pollution, the other half did not. Majority of the teachers had basic knowledge and understanding of various aspects of domestic pollution. However, a significant number of teachers were ignorant on certain aspects concerning chemical and noise pollution among others. 3) The teachers' perceptions of various aspects of domestic pollution influenced the areas of emphasis in their teaching. 4) The activity most teachers indicated they encourage often was the cleaning in and around the classroom; while the one least often encouraged was the use of organic pesticides to kill pests. 5) Other additional activities the teachers indicated they encouraged included proper refuse disposal, tree-planting and the use of renewable energy among others. The researcher concluded that most primary school teachers teaching Home Science had appropriate perceptions of domestic pollution and all indicated a positive attitude towards improving the quality of the environment. Further research in the area under study is recommended. It should involve a larger sample and a wider scope.

Reducing Environmental Noise Impacts: A USAREUR Noise Management Program Handbook

Abstract: : Noise pollution is a major environmental problem faced by the US Army in Europe Noise-related complaints from German citizens can escalate into intense political issues in German communities This in turn hampers efficient operation of military training and often times threatens the Army's mission In order to remedy these problems, USAREUR has developed a noise management program A successful noise management program will limit the impact of unavoidable noise on the populace This report, a component of the noise management program, is a reference document for noise management planning It contains guidelines and rules-of-thumb for noise management This document contains procedures which operation and training level personnel can understand and apply in their day to day noise management planning Noise mitigation tips are given Basic technical information that will aid in understanding noise mitigation is provided along with noise management through land use planning Noise management for specific components of the military community, (airfields, base operations, training areas, and housing and recreation areas) are addressed The nature of noise generated, means of noise abatement at the source, path, and receiver (both physical and organizational/public relations methods), and a case study example are described