护听器声衰减值的3种测试方法

关于护听器声衰减能力的评价,目前有好几种方法都有大量文献充分地论证。本文介绍了3种标准化的评价方法：真耳听阈衰减法（Real～ear attenuation at threshold,PEAT）,真耳内置麦克风（Microphone in real ear,MIRE）,和声学仿真测量装置（Acoustical test fixture,ATF）方法。讨论了评价护听器声衰减能力,这3种方法各自的优缺点和适用范围。REAT方法是评价护听器声衰减值最准确的方法之一,目前被国际标准普遍采用。     

Determining Attenuation of Impulse Noise With an Electrical Equivalent of a Hearing Protection Device

Determining the effectiveness of impulse noise attenuation with hearing protection devices (HPDs) is an important part of their selection. Measuring impulse noise parameters under an HPD would involve exposing subjects to impulses with a high peak sound pressure level. This paper presents a computational method of determining impulse noise parameters under the cups of earmuffs. Calculations are done using the transfer function of earmuffs, determined with Shaw’s electrical equivalent of an HPD, taking into account the design parameters of earmuffs. The developed method was used for calculations in the presence of impulse noise generated by gunshots. To verify the computational method, the results of these calculations were compared with the results of measurements.     

护听器个人防护值验证技术

本文介绍了关于护听器实际防护值的研究数据,和用于护听器个人防护效果验证的方法,以及3ME-A-RfitTM听力防护验证系统。研究表明,护听器的标称降噪值对其实际防护值的指示性非常差,目前也还没有一个可靠的方法来使用护听器的标称值。3ME-A-RfitTM听力防护验证系统是使用实地真耳内置麦克风(F-MIRE)方法,在实际工作现场中快速、定量地测定护听器在具体使用者身上取得的个人声衰减值(PAR),让安全管理人员对员工实际获得的防护水平有清晰的了解。     

Most Comfortable Listening Level and Speech Attenuation by Hearing Protectors

Hearing protectors attenuate both the background noise and the useful sounds embedded in noise such as the sounds of speech and warning signals. An effective hearing protector is one that attenuates background noise while leaving sufficient energy of speech and warning signals to reach the ear of the worker. At present, however, there are no established criteria for assessing effective change in speech-to-noise ratio caused by hearing protection devices (HPDs). One such criterion could be a change in most comfortable (listening) level (MCL) for speech caused by the presence of HPDs. In this study the HPD-related shift in MCL for speech presented in quiet was measured and compared with two measures of noise attenuation: Noise Reduction Rating (NRR) and high–medium–low (H–M–L). The results indicate that the MCL shift may be a sensitive measure of speech attenuation by HPDs, which together with the appropriate H–M–L may describe technical properties of HPDs.     

护耳器使用现状评述

研究表明：护耳器现场使用实际声衰减值低于实验室值,其原因是护耳器的实验室测量条件较为严格。工人在现场实际使用护耳器时,未能同实验室中的受试者一样佩戴护耳器,因而获得的护耳器声衰减比实验室所测得的值低。另一方面,在８小时强噪声环境中工作期间,未自始至终佩戴护耳器,则也达不到预期的保护听力的效果。笔者还综合分析和评述了护耳器现场使用时实际声衰减值降低的原因,并提出了一些有益的建议     

城市轨道交通站台噪声测量研究

为研究城市轨道交通高架和地下站台噪声的规律和特点,选取某条线路中的3个高架站台以及3条线路中的7个地下站台进行实地测量,并对测量结果进行分析。研究结果表明:地下站台LAeq值都低于标准限值80 dB(A);站台的中心测点列车进站LAeq值和列车出站LAeq值都非常接近,使用T检验结果得出各站台中心测点列车进站LAeq值和列车出站LAeq值不存在显著差异（P>0.05）;站台测量时要考虑大客流带来的喧闹声;站台最大噪声值是列车出站时,位于站台列车车头停止位置。     

煤矿井下主要设备噪声源测定分析研究

煤矿地面噪声防治已经受到人们的重视,但煤矿井下噪声仍被人们所忽视,对它研究的不多。通过对开滦集团东欢坨煤矿和荆各庄煤矿进行井下噪声测量,制作噪声频谱图和噪声传播衰减趋势图,分析井下噪声的频谱特性和衰减变化,为煤矿井下降噪提供依据。结果表明所测得的煤矿井下各点噪声强度均大于90dB（A）,且以中高频率为主,所以应当采取相应的针对性措施为煤矿井下进行降噪处理。     

Design of Optimal Noise Hazard Control Strategy With Budget Constraint

An analytical design procedure to determine optimal noise hazard control strategies for industrial facilities is presented. Its objective is to determine a set of appropriate noise controls to eliminate or reduce noise levels so that workers ‘ daily noise exposure does not exceed a permissible level. From a given noise control budget, engineering controls will be firstly implemented, followed by administrative controls, and then the use of hearing protection devices. Six optimization models are developed and sequentially applied to select appropriate noise controls without exceeding the budget. Numerical examples are presented to demonstrate the application of the proposed design procedure.     

Design of optimal noise hazard control strategy with budget constraint.

An analytical design procedure to determine optimal noise hazard control strategies for industrial facilities is presented. Its objective is to determine a set of appropriate noise controls to eliminate or reduce noise levels so that workers' daily noise exposure does not exceed a permissible level. From a given noise control budget, engineering controls will be firstly implemented, followed by administrative controls, and then the use of hearing protection devices. Six optimization models are developed and sequentially applied to select appropriate noise controls without exceeding the budget. Numerical examples are presented to demonstrate the application of the proposed design procedure.     

护耳器声衰减性能评价方法的分析研究

简要介绍了最新护耳器声衰减性能评价方法和评价量,利用其方法对美国现今使用的耳塞进行了计算。对本文所涉及的３种评价方法进行分析、比较和评述,并提出建议     

单兵用主动式听力保护技术研究现状分析

战场噪声是造成单兵听力损伤的重要原因,通常要求单兵处于大于85dBA的噪声环境中需佩戴听力保护装置。听力保护装置通常包括耳罩式和耳塞式。新型单兵用耳塞式听力保护装置具有听力保护、环境声音的监听、持续及脉冲噪声抑制、通信接入等多种功能。     

某大型机加车间数控机床噪声暴露特点与分析研究

为研究大型机加车间噪声现状和特点,选取某大型机加车间数控机床开展现场实测,并对噪声测量结果进行分析。结果显示:数控机床产生的噪声是非稳态噪声;数控机床产生的噪声在车间传播,声场分布不均匀;加工某转向工件频率在500～5 300 Hz,峰值频率分别为500,800,2 000,5 000 Hz;对机加数控机床操作岗位工作人员的8 h噪声暴露量进行测量,测量值为89.2 dB(A)。研究结果表明:评价大型机加车间噪声,测量重点应选在机床操作岗位和人行通道;应重点关注被测机床周围20 m内的噪声值;机加工作场所测量时间段的选择取决于作业持续时间。     

On Evaluation and Localization of Auditory Warning Devices for Adequate Audibility

This paper presents an analytic procedure to assist safety practitioners in evaluating the audibility of an existing auditory warning system in their workplaces. Two alarm location models are described: (a) a model with an unknown signal sound level, and (b) a model with a known signal sound level. A heuristic algorithm to determine a minimum number of alarm devices and their locations so that the warning signals can be clearly heard by workers is also proposed. The algorithm considers the ambient noise level, noise levels generated by individual machines, locations where workers are likely to be present, and noise levels at worker locations. From the numerical examples and the computation experiment, both the optimization and heuristic approaches yield solutions that satisfy the 15-dBA constraints. The heuristic approach is efficient in solving large alarm location problems due its capability to find near-optimal solutions within reasonable computation time.     

A new multiple-risk map approach to solve process plant layout considering safety and economic aspects

Mathematical models used to optimize the process plant layout (PPL) with risk reduction have four primary objectives, which are related to the minimization of land, pumping (pipe system), protection system devices, and risk costs. Moreover, these models are of two types: continuous plane models (CPM) and grid-based models (GBM); however, the nonconvexity of the CPM models makes difficult to achieve the global optimum, because it is formulated as Mixed-Integer Nonlinear Programming (MINLP). Thus, the risk map approach has been implemented with the grid-based models to solve problems of process plant layout focused on finding the best possible solution. However, these risk map formulations present important limitations, mainly related with the use of protection devices and the occupied area. Therefore, a new GBM-MILP formulation is proposed to optimize the selection of protection devices and minimize the occupied area. The risk is reduced through the investment on safety devices instead of considering the increase of separation distances. The proposed model was used to solve the layout problem of an ethylene oxide process, and the results was compared with a process layout reported in the literature. The results show that the model can provide the best possible solution; however, the time spent in the calculation is considerably greater than that reported for continuous plane models. Finally, the model can be used by decision-makers to evaluate different layout options for several explosion scenarios, during the early stages of the plant design.     

京沈客运专线框架式声屏障降噪效果研究

高速铁路经过城市建成区两侧分布有高层住宅建筑,普通直立式、折角式声屏障对于较高楼层难以有效阻隔噪声,框架式声屏障具有更好的降噪效果,对其降噪效果的研究越来越成为工程设计中噪声治理选取的重要依据。在阐述框架式结构声屏障插入损失确定方法的基础上,分别采用边界元法、统计能量法预测框架式声屏障的降噪效果,通过实际案例加以类比验证,得出京沈客运专线框架式声屏障降噪效果。     

基于气象服务信息的应急物资配送路径选择

为构建科学的应急救援体系,基于气象服务信息制定更合理的应急物资配送路径方案。将突发灾害下典型的"单出救点、单受灾点"应急物资配送网络结构作为研究对象。运用衰减系数反映气象条件对物资配送速度的实时影响。构建以满足时间限制和需求量要求为前提的应急物资配送路径选择模型。设计算例进行数值仿真和参数分析,将求解结果与传统最短路径法所选路径方案进行对比分析。结果表明:气象服务提供的衰减系数和途经各区域灾害强度等关键信息对配送路径的优化决策有重要影响。     

医疗器械中人的可靠性分析

医疗器械产品是一类直接关系到人生命健康的特殊产品.长期以来,医疗器械产品的使用安全性一直是亟待解决的重大问题.在医疗器械产品设计中进行人的可靠性分析能够进一步提高医疗质量,防止医疗事故.但是,这方面的工作目前还处于起步阶段.本文主要从医疗器械人的可靠性方面人手,定性及定量的分析人在使用器械时的可靠性问题.用SHEL模型来定性的分析医疗器械中人的可靠性的影响因素；用故障树方法及概率树对具体的多功能医用手术床进行定量分析；用第二代可靠性分析方法-CREAM解决定量分析的主观性问题；最后提出建立医疗器械人的可靠性数据库.以此为医疗器械产品设计提供了人的可靠性分析的方法.     

高速铁路轮轨噪声及其控制措施

高速铁路的发展,列车速度的提高使铁路噪声污染也急剧增加,不可避免地对人类生活带来了极大的负面影响,因此,发展高速铁路必须考虑噪声问题。笔者从噪声对人类产生的负面影响入手,分析了高速铁路噪声产生的原理,论述了轮轨噪声的组成及各组成部分对轮轨噪声的贡献程度。结合铁路噪声的评价指标,借鉴国内外相关经验,分别从轨道结构和车辆两方面详细阐述了控制轮轨噪声的措施。并总结了为了控制轮轨噪声,今后应重点发展的方向和重视的问题,对降低高速铁路轮轨噪声具有一定的指导意义。