Detection and Classification of Motor Vehicle Noise in a Forested Landscape

Noise emanating from human activity has become a common addition to natural soundscapes and has the potential to harm wildlife and erode human enjoyment of nature. In particular, motor vehicles traveling along roads and trails produce high levels of both chronic and intermittent noise, eliciting varied responses from a wide range of animal species. Anthropogenic noise is especially conspicuous in natural areas where ambient background sound levels are low. In this article, we present an acoustic method to detect and analyze motor vehicle noise. Our approach uses inexpensive consumer products to record sound, sound analysis software to automatically detect sound events within continuous recordings and measure their acoustic properties, and statistical classification methods to categorize sound events. We describe an application of this approach to detect motor vehicle noise on paved, gravel, and natural-surface roads, and off-road vehicle trails in 36 sites distributed throughout a national forest in the Sierra Nevada, CA, USA. These low-cost, unobtrusive methods can be used by scientists and managers to detect anthropogenic noise events for many potential applications, including ecological research, transportation and recreation planning, and natural resource management.     

Open-plan office noise: Cognitive performance and restoration

The aim of the present study was to investigate cognitive, emotional, and physiological effects of two open-plan office noise conditions (high noise: 51 LAeq and low noise: 39 LAeq) during work in a simulated open-plan office, followed by four restoration conditions (river movie with sound, only river sound, silence, and office noise) after the work period. Students (N = 47) went through one practice session and two experimental sessions, one each with the low and high noise conditions. In each experimental session they worked for 2 h with tasks involving basic working memory processes. We also took physiological measures of stress (cortisol and catecholamines) and self-reports of mood and fatigue. Analyses indicate that the participants remembered fewer words, rated themselves as more tired, and were less motivated with work in noise compared to low noise. In the restoration phase the participants who saw a nature movie (including river sounds) rated themselves as having more energy after the restoration period in comparison with both the participants who listened to noise and river sounds. Remaining in office noise during the restoration phase also affected motivation more negatively than listening to river sounds or watching the nature movie. The findings bear on the appropriateness of open-plan office designs and the possibilities for restoration available in office settings.     

大型环境模拟试验系统噪声防护及管理方法

以大型复杂环境模拟试验系统为例,通过对系统各设备及控制间噪声数据的测量,详细分析了噪声的来源和特性,并从消声、吸声、隔声等方面采取了一些有效的措施。结果表明,取得了较好的效果,且对试验设备不造成任何负面影响,同时也为工程实际中的噪声治理提供了借鉴。     

四川省噪声污染现状与防治对策

随着城镇化的进程不断加快,环境噪声污染问题日益突出,为了创建和谐社会,实现人类社会的可持续发展,还公众一个宁静安逸的生活环境,必须做好噪声的控制和消减工作,本文根据对2012年四川省噪声污染现状及治理方法的调研,分析在噪声防治过程中存在的问题,提出了健全噪声管理机制、声环境功能区划定或调整、严格声环境污染项目审批等与四川省实际情况相适应的的噪声防治对策。     

Traffic noise and executive functioning in urban primary school children: The moderating role of gender

The objective of this study was to examine the relationships between noise and school children's executive functioning (EF). The study included 311 children (146 boys and 165 girls) aged 7–11 years, who lived in the center of Belgrade. Teachers rated children's EF on a standard scale evaluating their ability to work independently in a focused manner to achieve an end goal as well as children's ability to follow directions carefully. Residential noise exposure was estimated in three daytime intervals, one evening interval and two nighttime intervals in the middle of the streets where children lived. School noise exposure was measured on three different school days in front of children's schools. Socioeconomic status (mother's highest level of education and family income) was used as a statistical control. There were no significant main effects of ambient noise levels on EF, however, a significant interaction indicated adverse noise impacts on boy's EF. We discuss possible reasons for male EF vulnerability to noise.     

Understanding and Managing Experiential Aspects of Soundscapes at Muir Woods National Monument

Research has found that human-caused noise can detract from the quality of the visitor experience in national parks and related areas. Moreover, impacts to the visitor experience can be managed by formulating indicators and standards of quality as suggested in park and outdoor recreation management frameworks, such as Visitor Experience and Resource Protection (VERP), as developed by the U.S. National Park Service. The research reported in this article supports the formulation of indicators and standards of quality for human-caused noise at Muir Woods National Monument, California. Phase I identified potential indicators of quality for the soundscape of Muir Woods. A visitor “listening exercise” was conducted, where respondents identified natural and human-caused sounds heard in the park and rated the degree to which each sound was “pleasing” or “annoying.” Certain visitor-caused sounds such as groups talking were heard by most respondents and were rated as annoying, suggesting that these sounds may be a good indicator of quality. Loud groups were heard by few people but were rated as highly annoying, whereas wind and water were heard by most visitors and were rated as highly pleasing. Phase II measured standards of quality for visitor-caused noise. Visitors were presented with a series of 30-second audio clips representing increasing amounts of visitor-caused sound in the park. Respondents were asked to rate the acceptability of each audio clip on a survey. Findings suggest a threshold at which visitor-caused sound is judged to be unacceptable, and is therefore considered as noise. A parallel program of sound monitoring in the park found that current levels of visitor-caused sound sometimes violate this threshold. Study findings provide an empirical basis to help formulate noise-related indicators and standards of quality in parks and related areas.     

MODERATING THE STRESS IMPACT OF ENVIRONMENTAL CONDITIONS: THE EFFECT OF ORGANIZATIONAL COMMITMENT IN HONG KONG AND CHINA

The purpose of the study is to investigate the relationship between environmental conditions and employee health in Chinese white and blue-collar samples, and to examine the role of organizational commitment as a stress moderator. Data are collected using a self-administered questionnaire. The participants are 158 white and 138 blue-collar workers in Hong Kong and 372 blue-collar workers in China. The results show that environmental conditions (including ventilation, workable space, illumination, temperature, noise, air pollution, and freedom to move around at work) are positively related to job satisfaction, and physical and mental well-being. These relationships are particularly true in the Hong Kong white-collar and China blue-collar groups. Further, organizational commitment moderated some of the relationships between environmental conditions and health. Inconclusive results of the buffering role of organizational commitment are obtained.     

Changes in excretion rates of stress hormones in medical staff exposed to electromagnetic radiation

The aim of this paper is to study the effect of electromagnetic radiation (EMR) on the excretion rates of stress hormones of medical staff in physiotherapy. The excretion rates of stress hormones cortisol, adrenaline and noradrenaline were followed during morning shift in 15 female physiotherapists using RIA kits and a spectrofluorimetric method. The mean number of treatments with EMR emitting devices per month and the emission of each device was assessed. A control group of nurses, matched by age, sex and work task was used. The psychosocial factors were evaluated and no differences between the two groups was found. Calculations of the individual EMR exposure show levels above the ICNIRP guidelines. Significantly higher excretion rates of cortisol, adrenaline and noradrenaline among the studied physiotherapists in comparison with the control group of nurses were found. In conclusion, our data showed that EMR influenced the excretion rates of stress hormones of medical staff in physiotherapy.     

Assessing the influence of urban geometry on noise propagation by using the sky view factor

The impact of traffic noise can be prevented by suitable planning measures. This study analyses the relationship between urban geometry and traffic noise, recognizing that the arrangement of buildings and streets greatly influences urban noise. The study was carried out in Braga, a medium-sized Portuguese city, by selecting locations with different urban geometries. At each site, the equivalent continuous sound level was measured. Furthermore, the urban geometry was evaluated by using the sky view factor, a parameter which shows the degree of sky obstructed by buildings. Results show an inverse proportionality between noise and the sky view factor. The highest noise levels were found in areas with a low sky view factor. The results also indicate that the sky view factor is a parameter which can potentially be used in research on urban noise.     

四川省自贡市声环境质量监督性监测结果分析与建议

开展了四川省自贡市城市声环境质量监督性抽测工作,进行了历史监测数据核查、仪器设备检查、日常质控情况检查、现场比对监测与监测点位核查,抽测结果显示自贡市声环境质量监测工作在监测数据管理、仪器设备管理、监测点位有效性及监测人员业务素质等方面存在一些问题,提出了加强声环境监测技术贮备和人员培养,及时调整监测点位,加强质量管理等建议。     

石化炼制企业噪声治理探讨

文章通过对石油化工炼制企业噪声的分析,相对不同场所噪声源进行不同治理方案的探讨,就某石化公司典型装置蒸馏装置为例进行噪声源及相应的治理方案分析,选择在临厂界处建设隔声屏障,对声源进行有效的阻隔,监测结果表明:隔声屏障起到了有效的隔声降噪作用,厂界噪声达GB 12348-2008《工业企业厂界环境噪声排放标准》。     

高速公路声敏感点降噪措施改善研究

以四川省某高速公路沿线的居民噪声投诉案件为例,开展了敏感点声环境质量现状及既有声屏障措施效果调查分析,并采用文献调研及Cadna/A软件建模计算的方法,分别从噪声源、噪声传播途径、敏感建筑物三个层次进行了敏感点降噪措施改善研究,研究结果可为高速公路营运单位解决实际噪声扰民问题提供技术支撑,研究过程及方法可供类似项目参考借鉴。     

变压器噪声控制技术及装备

介绍并分析了某城市110kV变电站的变压器噪声源特点,在满足其运行工艺、设备性能、声学效果、经济、安全的条件下,设计开发了特殊的隔吸声结构、消声结构等变压器降噪装置,并成功应用于工程实践中,取得了理想效果。     

城市电厂大型机力通风冷却塔的噪声控制

针对城市电厂大型机力通风冷却塔的噪声污染,以北京太阳宫燃气热电冷联供工程中应用的机力通风冷却塔噪声控制为例,通过分析研究冷却塔各声源不同的频谱特性和传播特性,并根据厂界噪声控制目标计算声源的超标量和设计降噪量,采取隔声、消声和吸声等综合集成的噪声控制技术,设计开发了大型机力通风冷却塔降噪消声装置,取得了理想效果,使厂界噪声达到I类标准,为低噪声机力通风冷却塔的声学设计提供了工程实践参考。     

噪声防治技术在化工装置中的研究应用

为了降低4500 Nm~3/a氢气联产10000 t/a甲醇装置的噪声及减少其对岗位员工和周边居民的影响,辽河油田公司油气工程技术处针对该装置噪声特点及其对员工的健康危害进行分析,采用吸声、隔声、缓声技术对该装置进行整治。治理后,该装置噪声值由97 dB(A)降至80 dB(A),符合GB Z1-2002《工业企业设计卫生标准》;同时,厂界噪声值低于65 dB(A),符合GB 12348-90《工业企业厂界噪声标准》第四类要求。     

四川省城市声环境质量状况与分析

根据四川省2007年城市功能区声环境、城市区域声环境和道路交通声环境数据,阐明全省城市声环境质量现状,分析城市声源构成、各等级声覆盖率及其变化趋势.与国内一般情况相比,四川省城市声源构成具有社会生活噪声影响范围更最广,交通噪声影响范围较小等特点.四川省城市环境质量状况总体上处于较好水平,且有逐年下降趋势.同时,存在部分不同程度的噪声污染区,甚至存在一定程度的重度污染区.     

城市居民区配套设备噪声频率特性分析

对绵阳市某居住区典型的配套设备噪声源进行分析，选取变配电房噪声、车库噪声、电梯井噪声、电梯控制室噪声、家用空调室外机、水泵房等6种典型噪声源。分析这些噪声源的频谱及低、中、高频段的能量比率。结果表明，各声源最大声压级所在频段以低频段最多（6种典型噪声中占5种），最大能量分布频段也是以低频段最多（6种典型噪声中占5种），因而低频噪声已经成为居住区中影响最大的噪声源。     

Aesthetic and affective effects of vocal and traffic noise on natural landscape assessment

National parks have mandates both to preserve and protect natural settings and to assist visitors in viewing and interacting with those settings. Considerable scholarship has examined the trade-offs between preservation and recreation goals, such as protection of a natural setting when some visitors want to experience it from noisy aircraft or ground vehicles. The current project expands on previous noise research that showed the presence of aircraft noise to be detrimental to aesthetic and affective environmental assessments. Participants rated 25 scenes under quiet conditions or while hearing 45 dB(A) or 60 dB(A) of either natural sounds (bird calls, breeze through foliage), natural sounds with aircraft sounds, natural sounds with ground traffic sounds, or natural sounds with human voices. Results indicated that the presence of any anthropogenic noise–air traffic, ground traffic, or voices–negatively impacted environmental assessments, and more so at louder levels, while the natural soundscape had little to no effect on assessments. Additionally, the presence of air traffic, ground traffic, and human voices significantly decreased participant ratings of serenity while also increasing ratings of hostility. These effects were strongest for scenes that were high in scenic beauty. Results are discussed in the context of sound quality management in national parks and other settings.     

Noise pollution monitoring during Diwali festival in Golden city Jaisalmer of Rajasthan, India

Noise is an important pollutant of environment causing various health hazards. In the present study, ambient noise levels were measured in two different areas within Jaisalmer city viz., commercial and residential area, on festive day and non-festive day (after) of Diwali. The results of noise level monitoring revealed the fact that due to higher amount of firecrackers on Diwali festival noise level was enhanced. The average equivalent noise level was increased from 61.94?dB to 72?dB (A) and 64.68?dB to 73.74?dB (A) on festive day, respectively, in selected residential and commercial areas, where noise was 30 and 13.44?% higher than standards of Central Pollution Control Board, New Delhi for residential and commercial areas, respectively.     

Health benefits due to reductions of CO levels

A method is presented by which an upper limit of the adverse health effect of existing ambient CO concentrations on the U. S. population can be estimated. The method is based upon estimating the primary human physiological response to CO concentrations (COHb%) for the population in terms of person-hour-COHb>1.5% resulting from the time exposure of the population to CO concentrations in excess of the federally designated ambient air quality standard. The estimates of person-hour-COHb>1.5% are for exposures only to ambient CO concentrations and do not take into account the additional CO exposure for people who smoke or have occupational exposures.We estimate that there were up to 30.9×10⁹ person-hour-COHb>1.5% in 1973 due to ambient concentrations in excess of the ambient 8-hour CO standard, with approximately 5×10⁹ person-hour-COHb>1.5% occurring West of the Continental Divide and 25.9>10⁹ person-hour-COHb>1.5% occuring East of the Continental Divide; of these 21.3×10⁹ personhour-COHb>1.5% occurred in New York City. It was also estimated that a 60% reduction in 1973 ambient concentrations of CO (corresponding to an automotive emmision standard of less than 15 g/mile) would be needed to reduce to zero the person-hour-COHb>1.5%. The maximum estimated effects on the U.S. population of increases in ambient CO concentration above 1973 levels are also presented.