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Scenario analysis and noise action planning: Modelling the impact of mitigation measures on population exposure 总被引:1,自引:0,他引:1
This paper reports on strategic noise mapping research conducted in Dublin, Ireland. Noise maps are constructed for the day–evening–night-time and night-time periods and levels of population exposure are estimated for the same periods. In methodological terms, the research uses the UK’s calculation of road traffic noise (CRTN) method for calculating noise levels in the study area. This method has been adopted as the interim calculation method by the Irish authorities responsible for meeting the obligations set out in the EU Environmental Noise Directive (END). The research also investigates the usefulness of three noise mitigation measures for ‘acoustical planning’ purposes: traffic reductions, speed reductions and erection of acoustical barriers. The results indicate that levels of population exposure during night-time are extremely high relative to guideline limits set down by the World Health Organisation. In addition, the results highlight the significant role that certain noise mitigation measures can play in good ‘acoustical planning’. 相似文献
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Cross-correlation methods were applied for the estimation of the power spectral density and modulation spectrum of underwater noise generated by moving vessels. The cross-correlation of the signal from two hydrophones allows the separation of vessel acoustic signatures in a busy estuary. Experimental data recorded in the Hudson River are used for demonstration that cross-correlation method measured the same ship noise and ship noise modulation spectra as conventional methods. The cross-correlation method was then applied for the separation of the acoustic signatures of two ships present simultaneously. Presented methods can be useful for ship traffic monitoring and small ship classification, even in noisy harbor environments. 相似文献
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HU Bo YANG DeSen SHI ShengGuo & SUN Yu Science Technology on Underwater Acoustic Laboratory Harbin Engineering University Harbin China 《中国科学:物理学 力学 天文学(英文版)》2011,(9)
Near-field acoustical holography (NAH) is a powerful tool for identifying noise sources and visualizing acoustic field. By recording the acoustic pressures in the near-field, the acoustic quantities in the whole 3-D field can be reconstructed and predicted. However, the current theory of NAH is not applicable to tracking large scale moving noise sources. Therefore, the hybrid near-field acoustical holography is developed for reconstructing acoustic radiation, which is derived from statistically optimized ne... 相似文献
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Jacques Chatillon 《Applied Acoustics》2007,68(6):682-698
Noise exposure of workers in industrial halls is mainly induced by noisy machines whose acoustical features are often globally known by Sound Pressure Level. The evaluation of the directivity of these noise sources can help to anticipate specific solutions for noise reduction.This study shows how the directivities of three wood-working machines have been characterized. Some characterisations have been achieved with a simple and fast acoustical intensity mapping which meets the constraints of industrial areas.When source directivity is evaluated, its influence on the noise field in industrial halls can be assessed. Some simulations and some experiments allowed the estimation of the noise field induced in workshops by both directional and omnidirectional sources. Comparison of the fields prove that the noise distribution is influenced by the source directivity if the halls are empty. As soon as the halls contain scattering objects, the directivity effect is reduced a lot and the noise field remains nearly the same far from the source whatever source used. Nevertheless, workers close to a machine are exposed to noise according to their position with respect to the machine. Exposure at the workplace can vary from 4 to 8 dB(A) according to the directivity of machines such as those measured in the trials. 相似文献
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为研究中国近海海洋环境噪声的空间差异性,揭示其形成原因,以同一海域同一季节两个测量站位的长期观测数据为研究对象,对比两个站位噪声谱级的差异.结合海洋信道和噪声源特性的影响,分析港口强噪声源到噪声采集站位的传播损失,发现在50~500 Hz频段传播损失差值和噪声谱级差值呈现较强相关性;对港口航船噪声源级的分析发现,该频段内源级相差20 dB左右,与休渔期前后航船密度差异相对应。试验分析和研究结果表明,南海北部海域50~500 Hz频段内海洋环境噪声与航船噪声源密切相关,两站位噪声空间差异由海区传播条件差异与航船噪声源级差异共同引起。 相似文献
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The automated real-time detection and classification of cetacean and anthropogenic sounds from deep-sea observatories can play a key role to study cetaceans in the field, to quantify the impact of anthropogenic sounds or to initiate mitigation measures during potentially harmful human activities. In the area of the NEMO-ONDE deep-sea observatory, sperm whales are often present together with heavy shipping. The spatial coincidence of both sound sources allows for the long term monitoring of their interaction. Some ships produce impulsive sounds and the automated separation of these impulses from sperm whale clicks is not a trivial task. As part of a detection, classification and localisation system for acoustic data from marine observatories, we present four modules performing the automated real-time classification of clicks from sperm whales and impulsive sounds produced by ships. First, two modules detect segments that contain impulsive sounds within a specifiable frequency band and return the impulses’ positions. Then, two modules classify the detected impulses as sperm whale clicks or ship impulses. Finally, at the level of 22 s segments, the classification outputs from individual impulses are combined into a decision on the presence of sperm whale clicks or ship impulses. The modules’ reliability was tested on data from the NEMO-ONDE observatory. Training and testing data were separated by more than 2 months, enabling to assess the consistency of the predictions over the long term. The automated separation between segments of the two classes was high with area under the ROC curve (AUC) values between 0.94 and 0.98. 相似文献
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To study the spatial difference of ocean ambient noise in offshore China and reveal its generation mechanism, the difference between the noise level(NL) of two stations is compared based on long-term observation data collected in the same season. Considering the influence of underwater acoustic channels and the characteristics of noise sources, the transmission loss level(TL) from the port ship noise sources to the measuring station is analyzed and it shows a strong correlation between the transmission loss difference(TLD) and noise level difference(NLD) at the band of 50-500 Hz. At the same time, the analysis of ship noise source level(SL) presents a difference about 20 dB between the two ports, corresponding to the variation of the ship density before and during the fishing moratorium. The results prove that the ambient noise is closely related to ship noise sources at this frequency band, and the noise difference between the two stations results from the transmission loss and the ship noise sources. 相似文献
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A pair-wise comparison experiment on subjective annoyance rating of nine different noise samples is the focus of this paper. These noise samples collected from some associated facilities in urban residential areas are classified into three different types according to their frequency characteristics, and their A-weighted levels are equalized at 65 dBA. Based on the assessment of judging errors and statistical validity analysis of each testee’s evaluating matrix, invalid data are eliminated. The results show that the percentage of testees who chose noise samples containing more low frequency components had an obvious downside trend with the descending degree of annoyance from ‘the most annoyed’ to ‘the least annoyed’. The result indicates that noise which has low frequency characteristic is more annoying than noise of other frequencies when their A-weighted level are the same. Therefore, A-weighted level cannot scientifically assess noise annoyance which contains low frequency components mostly. 相似文献
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Arnab Das 《Applied Acoustics》2011,(9):660-664
Study and characterization of distant shipping component of ambient noise in shallow water aid in design of passive surveillance algorithms and effective signature analysis of marine vessels. This letter presents the work carried out on real ambient noise recording in very shallow water condition close to a commercial port with heavy shipping activity to study and characterize the distant shipping noise component for variations due to tide. Ambient noise recording was carried out by a bottom mounted sensor at 30 m depth at regular interval for a period of over one month and the spectrum in the band 10–1.6 kHz was characterized for its diurnal spectral variation. The study concluded that the distant shipping noise component due to heavy small vessel activity in the nearby port resulted in up to 35 dB variation in the shallow water ambient noise in coastal areas that may have serious implication on passive surveillance algorithms performance in the vicinity if adequately not addressed. This is the first such effort in ambient noise measurement and characterization in the extremely shallow water channel condition prevalent in the tropical waters off the west coast of India. 相似文献
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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. 相似文献
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Environmental noise levels can vary over a wide range as a result of the diversity of site conditions and activities occurring during field measurements. This variability, extremely important for a correct measurement interpretation, is often a source of disagreement when applying standards and regulations, as there is no consensus about how to estimate and present it. The paper contributes to this technical debate by investigating the statistical variability associated with a large measurement database acquired under field conditions. The database consists of 2 week’s noise recordings at each of 50 separate locations in residential areas affected mainly by road traffic noise. The results show increased variability (standard deviations) at the lower values of either logarithmic or arithmetic mean LAeq over the time periods investigated. It is anticipated that the observed relationships may be of assistance when estimating the noise level variability and the uncertainty associated with a noise measurement affected by road traffic or other environmental noise sources. 相似文献
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Murray Hodgson 《Applied Acoustics》2004,65(1):69-89
The acoustical characteristics of 14 university classrooms at the University of British Columbia were measured before and after renovation—seven of these are discussed in detail here. From these measurements, and theoretical considerations, values of quantities used to assess each classroom configuration were predicted, and used to evaluate renovation quality. Information on each renovation was determined with the help of the university campus-planning office and/or the project acoustical consultant. These were related to the evaluation results in order to determine the relationship between design and acoustical quality. The criteria focused on the quality of verbal communication in the classrooms. Room-average Speech Intelligibility (SI) and its physical correlate, Speech Transmission Index (STI), were used to quantify verbal-communication quality. A simplified STI-calculation procedure was applied. The results indicate that some renovations were beneficial, others were not. Verbal-communication quality varied from ‘poor’ to ‘good’. The effect of a renovation depends on a complex interplay between changes in the reverberation and changes in the signal-to-noise level difference, as affected by sound absorption and the source outputs. Renovations which reduce noise are beneficial unless signal-to-noise level differences remain optimal. Renovations often put too much emphasis on adding sound absorption to control reverberation, at the expense of lower speech levels, particularly at the backs of classrooms. The absorption and noise contributed by room occupants has apparently often been neglected. 相似文献
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Investigation of the dose-response relationship for road traffic noise in Assiut, Egypt 总被引:1,自引:0,他引:1
Sayed Abas Ali 《Applied Acoustics》2004,65(11):1113-1120
A field study has been carried out in urban Assiut city, Egypt. The goals of this study are: (1) to carry out measurements to evaluate road traffic noise levels, (2) to determine if these levels exceeds permissible levels, (3) to examine people’s attitudes towards road traffic noise, (4) to ascertain the relationship between road traffic noise levels and degree of annoyance. The measurements indicate that traffic noise noise levels are higher than those set by Egyptian noise standards and policy to protect public health and welfare in residential areas: equivalent continuous A - weighted sound pressure levels (LA eq) = 80 dB and higher were recorded, while maximum permissible level is 65 dB. There is a strong relationship between road traffic noise levels and percentage of highly annoyed respondents. Higher road traffic noise levels mean that the percentage of respondents who feel highly annoyed is also increased. 相似文献
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Fabiano B. Diniz 《Applied Acoustics》2005,66(4):467-477
This work is aimed at studying the noise caused by the transformers found in electrical substations located in calm areas in the city of Curitiba, Brazil. Although the level itself reaching the nearby buildings is not high if compared to other noise sources commonly found in a large city, they produce an annoying noise due to its low frequency tonal components. Two substations and their surroundings have been analyzed and acoustically mapped. The results have shown that some houses receive up to 35 dB(A) near one of the substations, which may led to some discomfort. It has also been noticed that a good planning of a substation, mainly of the firewalls, may help putting the houses under acoustical shadows. 相似文献
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McKenna MF Ross D Wiggins SM Hildebrand JA 《The Journal of the Acoustical Society of America》2012,131(1):92-103
Underwater radiated noise measurements for seven types of modern commercial ships during normal operating conditions are presented. Calibrated acoustic data (<1000 Hz) from an autonomous seafloor-mounted acoustic recorder were combined with ship passage information from the Automatic Identification System. This approach allowed for detailed measurements (i.e., source level, sound exposure level, and transmission range) on ships of opportunity. A key result was different acoustic levels and spectral shapes observed from different ship-types. A 54 kGT container ship had the highest broadband source level at 188 dB re 1 μPa@1m; a 26 kGT chemical tanker had the lowest at 177 dB re 1 μPa@1m. Bulk carriers had higher source levels near 100 Hz, while container ship and tanker noise was predominantly below 40 Hz. Simple models to predict source levels of modern merchant ships as a group from particular ship characteristics (e.g., length, gross tonnage, and speed) were not possible given individual ship-type differences. Furthermore, ship noise was observed to radiate asymmetrically. Stern aspect noise levels are 5 to 10 dB higher than bow aspect noise levels. Collectively, these results emphasize the importance of including modern ship-types in quantifying shipping noise for predictive models of global, regional, and local marine environments. 相似文献
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When noise mapping airports, the main noise sources are take offs and landings. But aircrafts’ taxi noise can also be important, and should be considered, for instance when there are residential buildings near the airport’s terminal.Main prediction tools, like Integrated Noise Model (INM), do not consider taxiing and standard outdoors noise predictions software applications must be used, to model taxi as industrial noise sources.This technical note shows frequency band sound power levels and directivity data for several aircrafts’ classes; so that an acoustic consultant can include taxi for noise mapping an airport. 相似文献