城市社区公园声景分布与景观特征关联性研究——以沈阳鲁迅公园为例*

城市社区公园为附近居民提供休憩与交往的公共空间,使用者是公园声景的创造者也是体验者。在公园设计中,将建成后的声景纳入考虑因素,在支持居民休闲活动的同时,创造良好的听觉环境体验,具有提升人居健康福祉和空间公平的现实意义。该研究以城市社区公园——沈阳鲁迅公园为研究对象,通过现场声景调查和使用者问卷,探究声景时空分布特征及居民体验;建构公园景观特征指数,探讨声景时空分布与景观特征的关联性。数据表明：自然声、居民活动声和周围道路交通声构成公园丰富的声景要素,园区内声压级、各类声事件感知显著性呈现不同的时空分布特征;受访者对典型声事件的愉悦性和干扰性评价呈现聚类性特征;以此为基础构建的表征公园景观特征的自然指数、人群聚集指数和交通影响指数,其分别与对应声事件的感知显著性显著相关。基于景观特征与声景分布的关联性,结合公园使用者的声景体验,提出与公园景观设计相结合的社区公园声景优化策略。     

几类典型环境声的主观评价及感知特性分析

近年来,通过“注入”调控声以降低交通噪声烦恼感的声频注入法受到广泛关注。以交通噪声调控研究为背景,通过成对比较评价了4类典型声音(实验一)和4类典型交通噪声(实验二)的烦恼感。结果表明,有调声(纯音和复音)烦恼度最高,自然声最低(海潮声最佳),蓝色噪声是仅次于海潮声令人感觉舒适的声音;被试对交通噪声和白噪声的评价存在明显的分类偏好。分析心理声学特征发现人对声音的感知依赖于多方面因素,但声刺激的某一因素(如粗糙度或音调特别高)特别突出则会引起极大的反感。构建不相似度二维感知空间,维度1反映了声音类型间的差异,维度2表征了被试对不同类型声音的烦恼度评价;并且通过相关分析发现它们与谱结构参量相关性较强。接下来的研究中,可以通过调整交通噪声的谱下降值和时域上升时间等参量使其谱结构更接近于自然声,从而降低噪声烦恼度。     

城市历史街区声景观及视听感知实验研究

城市历史街区声景观是空间环境的重要内容,直接影响人们的感知体验。论文以济南老城泉水街区为例研究城市历史街区的声景观并进行视听感知实验。结果表明,现场声元素喜好度显著高于实验室单听评价。鸟鸣、鹅叫声在现场和实验室评分都较高,大流速流量水景声在现场评分高而实验室评分低,小流速流量水景声在实验室和安静环境中评分较高,在吵闹环境中评分较低;声环境满意度与视觉景观优美度、声源组成喜好度、安静度之间存在显著正相关关系,与环境声压级存在显著负相关关系,但当较高的环境声压级主要由水声贡献时,声环境满意度明显提高;应从提高景观优美度、优化声源组成、降低环境声压级等方面进行声景观设计。论文为声元素喜好度和声环境满意度研究提供参考。     

基于GIS的高密度城市声景质量及其影响因素研究——以广州天河区为例

高密度城市空间背景下,声景质量对居民生活品质及身心健康具有显著影响.已有声景研究针对街区尺度的声景质量及其形成机制的探讨仍较为不足,尚未能为高质量宜居城市空间建设提供循证基础.该文基于地理学视角,通过声景漫步与问卷调查对广州市天河区南部声源类型、声环境特征、心理声学感知进行调查研究,旨在阐述城市街区尺度声景质量的空间特...     

近场声全息技术方法简介

随着科学技术的不断进步和人民生活水平的不断提高,噪声已成为环境和产品评价的一项重要指标,军事、交通运输、航空航天、工程机械等领域如何降低噪声水平也成为一个倍受关注的课题。噪声控制需要从声源控制、传播途径控制和受者保护三方面进行,一般来讲,声源控制是噪声控制中最根本、最有效的手段,而主要声源的定位与识别也是噪声控制工程的关键问题。从声源方面入手控制噪声就是要正确识别和定位声源,获得声源的声辐射特性。近场声全息技术突破了传统上通过测量声源表面振速信息计算声场辐射特性方法的瓶颈,而将声辐射问题转化为逆问题来…     

听觉感知中的噪声特性语义描述及其分析

基于听觉感知的噪声语义描述是噪声声品质研究的基础性问题,已有研究未将语义描述与噪声来源、频谱特性以及产品运行状态等物理信息联系起来。该文分别针对飞机舱内噪声、车辆噪声和空气净化器噪声这3组典型噪声开展了主观评价实验,并通过多维尺度分析和主成分分析描述了3组噪声的语义空间,系统分析了不同类型噪声的描述词,同时解释了描述词与噪声物理属性之间的联系。研究发现：飞机舱内噪声、车辆噪声以及空气净化器噪声可以由4维、4维和3维语义空间进行描述;不同类型噪声在语义描述中具有共性与个性,3组噪声语义的主要维度均与嘈杂感相关,而噪声的个性描述词与其声源的物理属性密切相关;进行声品质建模及应用时,应同时考虑噪声共性和个性描述词对听觉感知的影响,采取有针对性的措施以提升产品声品质。该文从听觉感知的角度进行了噪声特性的语义描述和分析,研究结果可为产品声品质以及噪声控制研究提供帮助。     

用Cadna/A软件预测桥梁交通噪声及应用分析

城市环境噪声的主要声源是车辆交通噪声，而城市高架道路经过区域的声环境影响比较复杂。城市高架桥路段两侧交通噪声排放主要在地面辅道和桥梁高架段，地面辅道交通噪声对临路第一排居民影响最大，而高架道路交通噪声对高层及后排居民的影响较大，范围更广。如何有效单独分析地面辅道交通噪声和桥梁高架交通噪声对周围环境的影响程度，将对交通噪声源的治理和对道路两侧不同范围内声功能区域建筑物的降噪措施提供理论依据。下面以上海沪闵路一沪杭公路地方越江大桥为例，分析了大桥的地面辅道和高架桥段敏感点的声环境现状，运用Cadna／A软件预测和分析越江大桥运营后地面辅道和桥梁高架段交通噪声各自对周围环境的影响，研究相关敏感地区的可能环境噪声状况，以及交通噪声影响的程度特征。     

冲击阻尼板的尺寸辨识与声线索提取

针对冲击板的物理属性辨识问题,研究了尺寸辨识的恒定声线索提取及其在听觉感知中所起的作用。设计并完成了三组主观评价实验,实验1分析了录音和合成声作为声刺激对尺寸辨识的影响。实验2和实验3分别针对铝板和木板的冲击声,通过不相似主观评价实验获得尺寸辨识的感知空间和对应力学空间维度,计算了不同声特征的信息精确度。最后,对比实验2和实验3的结果给出了尺寸辨识的恒定声线索,根据声线索与感知结果的相关性分析了听者的尺寸感知策略。结果表明,听者利用录音和合成声均获得了较好的尺寸辨识结果,且听者趋向于利用与尺寸有关的恒定声线索来完成感知任务,而忽略那些容易受其他声源属性影响的声信息。     

分布式压缩感知麦克风阵列多声源方位估计*

麦克风阵列已被广泛应用于音/视频会议等人机交互领域中时,多声源应用场景对声源方位估计性能提出了更高的要求。压缩感知(CS)声源定位算法将声源定位问题转化为信号的稀疏重构问题,相比传统的定位算法如相位变换加权（SRP-PHAT）和时延累加定位（DS）能够获得较高的定位性能,但多声源的存在一定程度上降低了稀疏程度,影响了CS重构性能。考虑到传统的CS定位算法并未利用多个连续语音帧之间声源空间向量的共同稀疏性,提出采用分布式压缩感知（DCS）理论以改善多声源的稀疏恢复估计的性能。仿真和实验结果表明,相比于传统定位算法和CS-OMP算法,DCS-SOMP算法在不同信噪比和不同声源强度的环境中,对多声源的方位估计都具有更好的定位性能和定位稳健性。     

浣花溪公园不同景观空间下的声景观特性研究

该文以成都市浣花溪公园为研究对象,通过对景观空间中声环境的综合研究探究其声景观特性,以此作为营造城市声环境的有效依据。文章首先通过声压级、声景观多样性指数和清晰度指数来定量探讨公园中17种景观空间下的声环境异同;然后以声景观舒适度指数和重要性-满意度-清晰度模型对12种声音类型进行主客观评价;最后通过声景观提升指数综合反映各景观空间下声景观的提升重点。研究发现,声景观会受到基底-覆盖-围合层面的不同类型和组合的影响,尤其在建设面开敞和绿色半开敞或绿色半封闭空间中得到社会声和自然声最为明显;声景提升应重点关注风声、鸟声、水声、昆虫声和音响声在对应景观空间中的利用。     

Perception of urban park soundscape

A number of studies have been initiated to explore how to improve the soundscape quality in urban parks. However, good soundscape quality in parks cannot be provided without a thorough understanding of the complex relationships among sound, environment, and individuals. As acoustic comfort is considered to be an important outcome of soundscape quality, this study investigates the relative impacts of the factors influencing acoustic comfort evaluation by formulating a multivariate ordered logit model. This study also explores the inter-relationships among acoustic comfort evaluation, acceptability of the environment, and preference to stay in a park using a path model. A total of 595 valid responses were obtained from interview surveys administered in four parks in Hong Kong while objective sound measurements were carried out at the survey spots concurrently. The findings unveil that acoustic comfort evaluation, besides visual comfort evaluation of landscape, also plays an important role on users' acceptability of the urban park environment. Compared with all the studied acoustic related factors, acoustic comfort evaluation serves as a better proxy for park users' preference to stay in urban parks. Hearing the breeze will significantly increase the likelihood of individuals in giving high acoustic comfort evaluation. Conversely, hearing the sounds from heavy vehicles or sounds from bikes will significantly reduce the likelihood in giving a high acoustic evaluation.     

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.     

An efficient robust sound classification algorithm for hearing aids

An efficient robust sound classification algorithm based on hidden Markov models is presented. The system would enable a hearing aid to automatically change its behavior for differing listening environments according to the user's preferences. This work attempts to distinguish between three listening environment categories: speech in traffic noise, speech in babble, and clean speech, regardless of the signal-to-noise ratio. The classifier uses only the modulation characteristics of the signal. The classifier ignores the absolute sound pressure level and the absolute spectrum shape, resulting in an algorithm that is robust against irrelevant acoustic variations. The measured classification hit rate was 96.7%-99.5% when the classifier was tested with sounds representing one of the three environment categories included in the classifier. False-alarm rates were 0.2%-1.7% in these tests. The algorithm is robust and efficient and consumes a small amount of instructions and memory. It is fully possible to implement the classifier in a DSP-based hearing instrument.     

Soundscape evaluations in two critical healthcare settings with different designs

Intensive care units (ICUs) have important but challenging sound environments. Alarms and equipment generate high levels of noise and ICUs are typically designed with hard surfaces. A poor sound environment can add to stress and make auditory tasks more difficult for clinicians. However few studies have linked more detailed analyses of the sound environment to nurse wellbeing and performance. This study is aimed at understanding the relationships between objective acoustic measures and self-reported nurse outcomes. Two 20-bed ICUs with similar patient acuity and treatment models were tested: A recently built neurological ICU and a 1980s-era medical-surgical ICU. The medical-surgical ICU was perceived as louder, more annoying, and having a greater negative impact of noise on work performance, health outcomes, and anxiety as compared to the neurological ICU. Surprisingly, there were little differences between two ICU sound environments based on traditional overall noise measures. The objective differences between the occupied sound environments in the two units only emerged through a more comprehensive analysis of the "occurrence rate" of peak and maximum levels, frequency content, and the speech interference level. Furthermore, mid-level transient sound occurrence rates were significantly and positively correlated to perceived annoyance and loudness levels.     

Acoustic comfort in large dining spaces

This study carried out a questionnaire field investigation in two typical large dining spaces. The results suggest that the acoustic comfort of diners has an influence on the comfort evaluation of the overall dining environment, and background noise is an important factor affecting the acoustic comfort evaluation of diners. The role of various individual sound sources in background noise has been investigated, considering general background music, speech sound, activity sound, and mechanical noise, and it has been revealed that background music, other diners’ speech sound and tableware’s impact sound has a dominant impact on the acoustic comfort evaluation of diners. Compared with the existence of background music in background noise, diners’ acoustic comfort evaluation is higher than that without background music. The loudness, articulation, noise level and preference degree of various individual sound sources are factors which affect diners’ acoustic comfort evaluation on sound sources. In terms of demographic and social factors, gender and the frequency of dining out have a significant impact on diners’ acoustic comfort evaluation.     

Acoustical characteristics of water sounds for soundscape enhancement in urban open spaces

The goal of the present study is to characterize water sounds that can be used in urban open spaces to mask road traffic noise. Sounds and visual images of a number of water features located in urban open places were obtained and subsequently analyzed in terms of psychoacoustical metrics and acoustical measures. Laboratory experiments were then conducted to investigate which water sound is appropriate for masking urban noise. The experiments consisted of two sessions: (1) Audio-only condition and (2) combined audio-visual condition. Subjective responses to stimuli were rated through the use of preference scores and 15 adjectives. The results of the experiments revealed that preference scores for the urban soundscape were affected by the acoustical characteristics of water sounds and visual images of water features; Sharpness that was used to explain the spectral envelopes of water sounds was proved to be a dominant factor for urban soundscape perception; and preferences regarding the urban soundscape were significantly related to adjectives describing "freshness" and "calmness."     

基于声舒适度的地下餐饮空间声级阈研究

为了确定地下餐饮空间内使用者主观声舒适度可接受时的声压级阈值范围,本文选取典型的封闭式地下餐饮空间作为研究对象,采用实地问卷与实测相结合的方法进行调研。结果表明:地下餐饮空间内整体环境舒适度主观评价偏低,声舒适度评价与整体环境舒适度评价具有强相关性,因此声环境是影响地下餐饮空间内整体环境舒适度的因素。在影响主观声舒适度评价的客观指标中,混响时间可不作为主要影响因素考虑;而背景噪声声压级是影响地下餐饮空间内声舒适度主观评价的重要指标。使用者声舒适度为可接受时,地下餐饮空间内背景噪声声压级阈值为70-75 dB(A)。     

Recreational boating traffic: a chronic source of anthropogenic noise in the Wilmington, North Carolina Intracoastal Waterway

The majority of attention on the impact of anthropogenic noise on marine mammals has focused on low-frequency episodic activities. Persistent sources of mid-frequency noise pollution are less well studied. To address this data gap, the contribution of 25 physical, biological and anthropogenic factors to the ambient noise levels in the Wilmington, North Carolina Intracoastal Waterway were analyzed using a principal components analysis and least squares regression. The total number of recreational vessels passing through the waterway per hour is the factor that had the single greatest influence on environmental noise levels. During times of high boat traffic, anthropogenic noise is continuous rather than episodic, and occurs at frequencies that are biologically relevant to bottlenose dolphins. As a daily part of resident bottlenose dolphins' acoustic environment, recreational boating traffic may represent a chronic source of acoustic harassment.