滨海公共空间声环境感知评价及影响因素*

滨海公共空间是滨海城市人居环境的重要组成部分,其声环境质量是影响公共空间环境体验的关键因素。本研究以青岛沿海岸线四类滨海公共空间（步道类、广场类、公园类、沙滩类）的声环境为对象,通过问卷调查和实地测量探索滨海公共空间声环境的特征、感知评价及其影响因素。结果表明：（1）滨海公共空间当前环境噪声水平基本不超过国家标准限值55dB(A) ,各类空间声环境客观特征显著不同：公园噪声水平最低,自然声源丰富;广场噪声水平最高,各种城市噪声较多;步道噪声水平较低,但受到交通噪声的影响;沙滩噪声水平较高,但以中低频的海浪声为主,比较稳定。（2）各类滨海公共空间的声源感知以自然声为主,但是广场的自然声源感知较少。此外,声环境的愉悦感评价普遍较高,但在事件感、吵闹度和总体满意度评价上具有显著差异：沙滩声环境总体评价最好,其次是公园,广场和步道的声环境则亟待改善。（3）交通噪声和最大声级Lmax对声环境的负面影响最为显著,此外受访者年龄也是影响滨海公共空间声环境感知评价的关键因素。研究结论可以为滨海公共空间声环境的优化设计提供理论依据。     

天山北坡绿洲城市车流量与对流层NO2垂直柱浓度关系研究

为探讨天山北坡河谷绿洲城市车流量与对流层NO₂垂直柱浓度（VCD）的关系,基于各城市车流量状况,利用地基多轴差分光谱仪（Mini MAX-DOAS）在2018年-2019年天山北坡经济带上的综合性大城市乌鲁木齐、工业型中等城市石河子和工业型小城市阜康市中心区连续固定监测,并沿城市交通主干道进行车载移动监测,研究车流量对NO₂VCD的影响,对比分析山盆体系河谷绿洲城市与中东部发达城市污染严重原因的差异。结果表明：（1）天山北坡大中小城市的车流量日均值大城市乌鲁木齐（1 406辆/5 min）远大于中小城市,中等城市石河子（203辆/5 min）和小城市阜康（185辆/5 min）差异并不显著（p＞0.05）,而各类城市NO₂VCD整体差异显著（p＜0.05）,其日变化峰值有所差异,表现为乌鲁木齐（22.613×1015 molec·cm-2）＞阜康（17.758×1015 molec·cm-2）＞石河子（15.272×1015 molec·cm-2）,三类城市的车流量和NO₂VCD的日变化趋势一致,都呈现出“早晚高,中午低”的变化趋势;季节变化中三类城市的车流量和NO₂VCD均为：冬春季＞秋夏季;（2）虽然早晚各监测点的车流量有所差异,但三类城市的车流都集中在市中心附近;移动监测数据表明,NO₂VCD高值出现在车流较高的市区,并且在各城市风向稳定时,下风向浓度大于上风向;由于居住空间差异,人们在城市各功能区间的活动,车辆流向和NO₂VCD都集中于人流密集的商业区,说明车辆对NO₂VCD具有较大贡献;（3）2009年-2019年10年间天山北坡大中小城市经济生产总值增长率在200%以上,乌鲁木齐、石河子机动车增长率超过北京、上海等发达城市,城市快速发展,并处于河谷绿洲地带,地势南高北低,冬季逆温层深厚,静风天数较多,采暖期长达6个月,造成冬季污染严重。天山北坡城市除人为污染排放外,自然因素对污染物形成聚集作用。     

第四届国际声与振动会议在圣彼得堡召开

第四届国际声与振动会议于1996年6月24－27日在俄罗斯的圣彼得堡召开．会议由国际声与振劝学会（InternationalInstituteofAcousticsandVibration，简称IIAV），俄罗斯噪声与振动控制学会等四个单位主办．来自40多个国家和地区的近500名代表出席了会议．会议论文集共收入论文316篇．会上交流了250篇，其中大会特约报告7篇：（1）听觉灵敏度解释的最新进展（SirJamesJamesLighthill,ENGLAND）；（2）有源噪声和振动控制遗传算法的应用（ColinHHansen，AUSTRALIA）；（3）湍流辐射噪声预报计算空气声学的进展（GeoffreyMLilley,…     

周期性冲击射流噪声特性数值研究

基于大涡模拟与声类比的方法对射流速度做周期性变化的平板冲击射流的噪声特性进行了数值研究。采用正弦、三角、锯齿和矩形4种典型的周期性波形,周期变化频率的范围是5～40 Hz,以不同监测点位置下的等效连续声压级为噪声大小的评价指标,研究了波形变化和周期频率变化对周期性冲击射流噪声特性的影响。结果表明:周期性冲击射流噪声大于稳态冲击射流噪声。矩形射流的冲击噪声最大,噪声分布波动剧烈,噪声频谱呈现高频特性,其他三种波形噪声分布较为均匀,噪声频谱呈现宽频特性。周期性冲击射流噪声随着周期变化频率的增加而增大。周期变化频率的改变对矩形波形频谱特性影响较小,对于其他三种波形的频谱特性影响较大。     

利用换能器电信号相位特征实时监测高强度聚焦超声治疗中的声空化

高强度聚焦超声(HIFU)激发的声空化可加速靶组织的热消融,但声空化的实时监测是一个亟需解决的问题。利用HIFU换能器驱动电信号的相位差与电阻抗之间的数学模型,建立了HIFU辐照及换能器驱动电信号、声空化信号实时检测实验系统,探究了HIFU辐照离体牛心组织过程中,换能器驱动电信号的相位差与B超影像灰度变化及宽频水听器检测到的次谐波和宽带噪声信号的变化规律。结果表明:当声空化发生时,换能器驱动电信号相位差的变化与水听器检测到的次谐波和宽带噪声信号变化具有一致性,通过相位差的变化可实现HIFU辐照靶组织中声空化的实时、精准监测,这为HIFU所致声空化的实时监测提供了一种有应用前景的解决方案。     

“中粒度噪声地图”概念及其构建思路

根据我国国情,提出用较少的优化监测点位形成中粒度噪声地图的构建方法.中粒度噪声地图的形成分为2个环节.一是噪声地图构建系统(平台)的形成,通过离线过程实现;二是噪声地图在线生成,包括贝济埃定义点z值测量、贝济埃曲面(线)调出、地面等效声源反演计算、等效声源的空间声场叠加.     

基于测试线法的风轮近尾迹辐射噪声研究

在风洞开口实验段,针对不同尖速比应用BSWA VS302USB振动噪声采集分析系统对水平轴风力机叶尖下游4个角度的测试线进行噪声测试.叶尖辐射声中的主要成分是叶片的旋转谐波声,其向风轮下游传播的过程中迅速衰减.在各测试线上,随着测点向风轮下游移动,叶轮辐射声迅速衰减,并在一定距离之后低于背景声,尖速比越高,风轮下游辐射...     

利用环境噪声互相关实现散射体无源成像

最近研究表明利用环境噪声的互相关可以恢复两点之间的时域格林函数(声脉冲响应),这一原理在文献中被称为格林函数恢复。基于此原理,通过对多个传声器所接收的环境噪声进行互相关处理,获取与散射体相关联的散射波的到达时延信息,结合最小二乘反演算法和改进克希霍夫移位算法,分别获得道路交通噪声场中石柱以及海浪噪声场中塑料桶的空间位置,且其估计结果与实际测量相一致。实验结果表明将环境噪声作为探测信号进行散射体无源成像是可行的。这为设计室内无源声监测系统以及通过海洋环境噪声实现对水中静默目标成像提供了新思路和有益参考。      

采用被动声监测方法识别波弗特海区域海洋水声环境

为了研究北冰洋冰下水声环境的噪声特性,对2016年中国第七次北极科考期间在波弗特海进行的声学观测实验获取的数据集,采用时间统计分析和频域谱分析方法进行了处理,讨论了处理结果与同时期获取的海洋、大气之间的联系。针对冰下噪声长期监测和北冰洋水声环境特性的准实时观测,确定了描述冰下水声环境特性的参数组,给出了处理方法和流程,用于基于被动声监测的水声环境识别,指导研究设计和硬件选择。回传的实测结果可以与已发表的结论进行比较,从而确切描述和理解北冰洋水声环境的变化。     

贝叶斯优化模糊聚类地级行政区声环境

声环境功能区划是噪声污染管理的重要手段,当前声环境功能区划研究大多是基于某个特定的地级行政区来进行的,难以反映各地级行政区声环境的异同。 该文基于134个地级行政区的人口、面积、各声环境功能区面积和及面积占比,进行地级行政区声环境表征和归一化处理。 以轮廓系数作为聚类有效性评价指标,基于贝叶斯优化模糊聚类方法对地级行政区声环境表征进行聚类分析。 通过本文方法与谱聚类、K-medoids聚类、高斯混合模型聚类的聚类性能对比,验证了该方法的有效性。 结果表明我国地级行政区声环境分为9类,城市规模和用地情况发生显著变化导致其声环境表征和归类发生变化后应重新评估当前噪声污染管理政策,并借鉴同类的地级行政区的噪声污染管理政策做出必要的调整。     

Effects of urban morphology on the traffic noise distribution through noise mapping: A comparative study between UK and China

Due to the rapid urban development and massive population increase in many eastern cities, the difference in urban density and morphology between typical western and eastern cities is becoming significant. This consequently makes the noise distribution in the eastern cities rather different from typical low density European cities. In this research, two representative cities with different urban densities, Greater Manchester in the UK and Wuhan in China, were selected, which have low and high average urban density respectively, and also have considerable differences in building form and traffic pattern. In the mean time, these two cities have similar urban scale and traffic amount. In each city, based on the urban morphological analyses considering urban land-use, building and road density, and noise source distribution, a number of typical urban areas, 500 * 500 m² each, were sampled. A noise-mapping software package was then used to generate generic noise maps, based on existing digital vector maps for terrain and building, and traffic data obtained by on-site measurements. The comparison results show that the average and minimum noise level in Greater Manchester samples is generally higher than that in Wuhan samples, while the maximum noise level in Wuhan samples is mostly higher. By developing a Matlab program, correlations have been analysed between noise distributions and the urban characteristics relating to urban density, such as the road and building coverage ratio. Overall, comparisons between these two typical cities have shown significant effects of urban morphology on the traffic noise distribution.     

水下声学浮标南中国海海洋环境噪声实测分析*

海洋环境噪声是多种自然噪声和人为噪声的复杂组合,其谱级大小和频率组成是影响声纳系统探测性能的重要参数,由于海洋环境噪声时空域特性是非常复杂的,因此需要对海洋环境噪声进行长时间和大范围的观测才足以分析其特性。本文通过在多剖面水下浮标平台基础上集成声学测量系统,研制出了一种具有海洋环境噪声监测能力的水下声学浮标平台,该浮标平台可多次上浮、下潜,具备原位坐底和定深漂流两种工作模式,能够连续观测海洋环境噪声时长多达几个月。利用2019年8月在南海海区组织的多台水下声学浮标组网试验数据,分析了不同频率海洋环境噪声谱级随时间变化特性,数据处理结果符合海洋环境噪声典型变化规律,试验表明,水下声学浮标可作为一种潜在的优势水下无人移动平台,用于长期监测海洋环境噪声特性。     

The implementation of low-cost urban acoustic monitoring devices

The urban sound environment of New York City (NYC) can be, amongst other things: loud, intrusive, exciting and dynamic. As indicated by the large majority of noise complaints registered with the NYC 311 information/complaints line, the urban sound environment has a profound effect on the quality of life of the city’s inhabitants. To monitor and ultimately understand these sonic environments, a process of long-term acoustic measurement and analysis is required. The traditional method of environmental acoustic monitoring utilizes short term measurement periods using expensive equipment, setup and operated by experienced and costly personnel. In this paper a different approach is proposed to this application which implements a smart, low-cost, static, acoustic sensing device based around consumer hardware. These devices can be deployed in numerous and varied urban locations for long periods of time, allowing for the collection of longitudinal urban acoustic data. The varied environmental conditions of urban settings make for a challenge in gathering calibrated sound pressure level data for prospective stakeholders. This paper details the sensors’ design, development and potential future applications, with a focus on the calibration of the devices’ Microelectromechanical systems (MEMS) microphone in order to generate reliable decibel levels at the type/class 2 level.     

Acoustical Aspects of Vocal Function Following Radiotherapy for Early T1a Laryngeal Cancer

We evaluated acoustic voice characteristics of 18 male patients undergoing radiotherapy. The subjects were seen for voice assessment preradiotherapy and at 1 month, 3 months, 6 months, and 1 year following radiotherapy. A multidimensional voice analysis computer program (IVANS, Avaaz Innovations, 1998) was employed to evaluate measures of traditional frequency and amplitude perturbation as well as time-based and linear prediction (LP) modeled "noise" parameters of the acoustic output in conjunction with perceptual judgments of overall vocal quality. The results indicate vocal deterioration of vocal function immediately following radiotherapy with gradual and significant improvement in acoustic and perceptual features over 9 to 12 months following the radiation treatment. Measures of glottal noise demonstrated higher sensitivity than frequency-based measures of voice perturbation, and with more consistent, less variable changes in acoustical voice output from the preradiation to the 12 month postradiation periods. Future research evaluating vowel type and acoustic perturbation measures with a larger sample of subjects over a longer time period seems warranted.     

ADVERSE HEALTH EFFECTS IN RELATION TO URBAN RESIDENTIAL SOUNDSCAPES

Noise pollution from road traffic in residential areas is a growing environmental problem. New approaches to turn the negative trend are needed. The programme “Soundscape Support to Health” will achieve new knowledge about the adverse health effects of noise pollution on humans and will investigate the link between well-being and health and perceived soundscapes for optimizing the acoustic soundscapes in urban residential areas. This paper will briefly present the programme and presents preliminary results from the first study of how various adverse health effects are related to individual noise exposures among individuals in residential areas with and without access to a quiet side of the dwelling.     

Noise mapping at different stages of a freeway redevelopment project – A case study in Brazil

In economically developing countries such as Brazil, India and China, rising levels of noise pollution are associated with the accelerated growth of cities and the increasing circulation of automotive vehicles. This paper presents the results of an acoustic evaluation conducted in areas adjacent to federal highway BR-116, part of which lies within the urban limits of the city of Curitiba in southern Brazil. In situ measurements were taken of the noise levels, from which noise maps were drawn in different stages of the implementation of the road restructuring project called the Green Line. After calibration, a computational model was used to evaluate an operational scenario of the highway in the future. The results of the mappings were compared with reference noise emission values established by municipal legislation. The maps revealed the existence of noise pollution in the urban stretch of the federal highway in all the scenarios [L_Aeq > 65 dB(A)]. Efforts to control environmental noise in cities are aided by computational models for urban planning. These models are extremely helpful for environmental management and decision-making by public authorities for solutions to potential environmental risks, as is the case of urban noise.     

A neural network based model for urban noise prediction

Noise is a global problem. In 1972 the World Health Organization (WHO) classified noise as a pollutant. Since then, most industrialized countries have enacted laws and local regulations to prevent and reduce acoustic environmental pollution. A further aim is to alert people to the dangers of this type of pollution. In this context, urban planners need to have tools that allow them to evaluate the degree of acoustic pollution. Scientists in many countries have modeled urban noise, using a wide range of approaches, but their results have not been as good as expected. This paper describes a model developed for the prediction of environmental urban noise using Soft Computing techniques, namely Artificial Neural Networks (ANN). The model is based on the analysis of variables regarded as influential by experts in the field and was applied to data collected on different types of streets. The results were compared to those obtained with other models. The study found that the ANN system was able to predict urban noise with greater accuracy, and thus, was an improvement over those models. The principal component analysis (PCA) was also used to try to simplify the model. Although there was a slight decline in the accuracy of the results, the values obtained were also quite acceptable.     

Acoustic comfort evaluation in urban open public spaces

This paper presents the results of an intensive questionnaire survey and objective measurements on soundscape, aiming at the evaluation of acoustic comfort in urban open public spaces. From summer 2001 to spring 2002, 9200 interviews were made for four seasons in 14 urban open public spaces across Europe. The results suggest that the subjective evaluation of the sound level generally relates well with the mean L_eq, especially when the sound level is below a certain level, which is 73 dBA on the basis of this study. However, considerable differences have been found between the subjective evaluation of the sound level and the acoustic comfort evaluation: people tend to show more tolerance in terms of acoustic comfort evaluation. The background sound level has been found to be an important index in evaluating soundscape in urban open public spaces - a lower background level tends to make people feel quieter. Analyses of individual sound elements show that the acoustic comfort evaluation is greatly affected by the sound source type - introducing a pleasant sound can considerably improve the acoustic comfort, even when its sound level is rather high. No significant difference was found among different age groups in terms of subjective evaluation of a sound level, whereas in terms of acoustic comfort, there were significant differences.