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。     

Hearing Protectors: Topicality and Research Needs

Occupational noise specialists do not generally recommend hearing protection devices (HPDs) as a preferred solution to noise risk prevention. Nevertheless, these devices are widely used and are in fact often necessary. Selection of an HPD should take into account comfort and the capacity for perceiving external signals, when they are worn. Current European regulations require that HPD attenuation be considered, when comparing noise exposure to limit values. However, HPD attenuation is effectively unknown under real-world conditions. Some methods are designed to give approximate attenuation values and these provide results within a wide statistical range. Field measurement methods and current standards have been developed to deal with this situation. The specific characteristic of impulse noise requires establishment of dedicated criteria and tools for HPD selection and testing. This paper introduces a number of avenues for research, which could be of assistance in improving HPD selection, qualification and design.     

某飞机维修公司个人听力防护用品使用情况调查分析

为了解听力防护用品使用过程中的问题,提高我国噪声暴露工人听力防护用品的使用率和有效率,选择噪声危害较大的某飞机维修公司的员工,进行听力防护用品使用情况的问卷调查。结果显示:该公司为员工提供耳塞和耳罩两种听力防护用品;员工的听力保护意识、使用情况较好,使用率达95%,但对听力防护用品相关知识的了解不够全面;能够在工作中一直坚持使用的工人较少,仅占11%,影响工人工作时间使用听力防护用品时间长短的因素主要是其舒适性。调查分析提示:在未来听力防护用品的生产过程中,需要进一步加强和改善舒适性的技术;政府、企业和个人3方面共同参与,降低职业性噪声暴露对工人听力的损伤。     

Application of Neural Networks in Active Noise Reduction Systems

Active noise reduction systems based on a control unit in the form of a finite impulse response filter assume the linearity of every single component. Neural networks, which have so far been seldom used in this field, are a kind of a filter with the ability to project nonlinear characteristics of an active noise reduction system. This paper presents some simulation research studies of active noise reduction systems based on neural networks. Also presented are results of the operation of systems with different levels of complexity as well as the influence of different parameters of a neural network and of the system itself on those results.     

Analysis of noise pollution in an andesite quarry with the use of simulation studies and evaluation indices

This paper presents the verification of two partial indices proposed for the evaluation of continuous and impulse noise pollution in quarries. These indices, together with the sound power of machines index and the noise hazard index at the workstation, are components of the global index of assessment of noise hazard in the working environment of a quarry. This paper shows the results of acoustic tests carried out in an andesite quarry. Noise generated by machines and from performed blasting works was investigated. On the basis of acoustic measurements carried out in real conditions, the sound power levels of machines and the phenomenon of explosion were determined and, based on the results, three-dimensional models of acoustic noise propagation in the quarry were developed. To assess the degree of noise pollution in the area of the quarry, the continuous and impulse noise indices were used.     

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。     

听力防护装备为健康筑起安全防线

随着我国工业的发展,噪声危害的分布范围越来越广,人们接触噪声的机会日益增多。长期接触噪声会对人体多个系统产生不良影响,其中尤以对听觉器官的损害最为突出。本文针对噪声的概念及噪声作业听力防护,分析了噪声对人体健康的影响因素及其主要损害,阐述了预防和控制噪声的个体防护装备,提出了噪声性听力损伤的自身防护早发现早防治措施。     

我国纺织噪声暴露现状及听力损失情况预测

通过对国内纺织业从业人员数量、工龄的统计和企业实地噪声情况的调查，借鉴ISO1999—1975（E）和其它相关方法预测我国纺织行业噪声暴露情况和从业人员的听力损失情况。经过预测，结果显示纺织从业人员暴露于85dB以下噪声的约有289．3万人，85～95dB约有381．2万人，高于95dB约有329．5万人；对于听力损失的预测，采用悲观和乐观法分别进行预测，结果表明约有100．57万人和21．61万人患有听力损失；结合实际调研情况对预测数据进行修正，结果表明目前我国纺织行业约有70．96万人患有听力损失。     

The Effects of Hearing Protectors on Auditory Localization: Evidence From Audio-Visual Target Acquisitioi

Response times (RT) in an audio-visual target acquisition task were collected from 3 participants while wearing either circumaural earmuffs, foam earplugs, or no hearing protection. Analyses revealed that participants took significantly longer to locate and identify an audio-visual target in both hearing protector conditions than they did in the unoccluded condition, suggesting a disturbance of the cues used by listeners to localize sounds in space. RTs were significantly faster in both hearing protector conditions than in a non-audio control condition, indicating that auditory localization was not completely disrupted. Results are discussed in terms of safety issues involved with wearing hearing protectors in an occupational environment.     

典型直升机噪声特点及其防护需求分析

直升机工作时,旋翼、尾桨及发动机传动系统可产生90dB （A）以上的噪声。本文从听感知角度分析了典型直升机噪声的声压级、特征频率及能量分布等特点及其防护需求。     

轻轨桥架声屏障优化设计研究

随着城市轻轨建设的发展,交通噪声污染逐渐引起人们重视。在轻轨桥架两侧设置声屏障是控制轨道噪声的重要措施之一。声屏障的高昂成本往往是由不合理的设计参数造成的,通过对目前声屏障设计方法进行分析,提出了轻轨桥架声屏障优化设计方法。该方法以声屏障建造成本为目标函数,以降噪要求为声学约束,综合考虑设置位置、高度和长度等设计变量的影响;由列车噪声1/3倍频程频谱计算插入损失,提高了优化过程中插入损失的计算精度。该优化设计法与目前设计方法对比,验证了声屏障优化设计在改善降噪性能和经济性能方面的优越性。讨论了设计参数对成本和降噪性能的影响,并且对轨边矮墙的降噪性能进行了分析,所获的结论对声屏障和轨边矮墙设计参数与形状的选择具有指导意义。     

Exposure to impulse noise at an explosives company: a case study

Impulse noise encountered in workplaces is a threat to hearing. The aim of this study was to assess the occupational exposure to impulse noise produced by detonation of dynamite on the premises of an explosives company. Test points were located on the blast test area (inside and outside the bunker) and in work buildings across the site. Noise propagation measurement was performed during 130 blast tests at nine measurement points. At every point, at least 10 separate measurements of A-weighted equivalent sound pressure level (L_Aeq), maximum A-weighted sound pressure level (L_Amax) and C-weighted peak sound pressure level (L_Cpeak) were made. Noise recorded in the blast test area exceeded occupational exposure limits (OELs). Noise levels measured in buildings did not exceed OELs. Results of the survey showed that for 62% of respondents, impulse noise causes difficulties in performing work. The most commonly reported symptoms include headaches, nervousness and irritability.     

A Study of Annoyance Caused by Low-Frequency Noise During Mental Work

This article presents the results of an analysis of annoyance caused by low-frequency noise (including infrasonic noise) that occurs at work stations located in offices. The tests covered measurements of acoustic parameters specific for this type of noise and a survey conducted in the working environment and in laboratory conditions at a model of a work station.     

基于FXLMS算法的矿用有源耳罩的研究

基于矿井中低频噪声突出,存在时间长、危害大,尤其周期性噪声比重较大,而传统降噪技术对其降噪效果并不明显,提出了基于fxlms 算法的自适应有源降噪耳罩降低矿井中的低频周期性信号,并采用离线建模方法建立了次级通道模型,利用MATLAB8.0拟合了64阶的滤波器,对 矿井中具有代表性的1kHz低频周期噪声和伴有随机噪声的1kHz低频周期性噪声进行了降噪仿真研究。结果表明:1kHz低频周期性噪声的降噪量 达到了30dB。而且在本模型下,随机噪声对低频周期性噪声的降噪效果几乎没有影响。     

农业作业者的听力防护

农业领域作业者的听力防护问题极少被关注,以农机噪声、养殖场噪声及其对作业者伤害调查数据看,农业噪声对作业者的危害不容忽视,给予作业特点和需求,需要选择合适的听力保护装备,并建立听力保护计划,保护在噪声环境中工作的农业作业者。     

A Digital Filter for the State Estimation of Impulsive Noise Under the Existence of a Background Noise and its Experiment in the Work Environment

In the actual work environment, a specific objective noise, like machine and industrial noises, shows impulsive fluctuation form. Furthermore, it often occurs that a specific noise is partially or completely contaminated by background noise. In that case, the fluctuation wave form of the specific noise has to be estimated moment by moment in order to evaluate and/or improve the work environment. In this study, a digital filter for estimating an impulsively fluctuating specific noise is proposed. More specifically, after introducing a generalized time series regressive model of the specific noise, a method for estimating the impulsive noise based on an observation contaminated by the background noise is theoretically derived. Furthermore, the proposed method is applied to the actual task of estimating an industrial impact noise.     

机场周围飞机噪声评价指标的应用及探讨

通过对某机场周围飞机噪声一个完整航班周期的监测,分析现有飞机噪声测量方法和评价指标(计权等效连续感觉声级LWECPN)的局限性,对比了连续监测24 h与连续监测一周评价结果的差异,提出以最大A声级LAmax作为补充评价指标的建议.     

利用主成分分析法简化甲烷/空气层流预混火焰的反应机理

利用主成分分析(Principal Component Analysis)的方法对甲烷/空气氧化的详细化学反应机理进行了简化，在低压层流预混火焰条件下进行了计算，计算结果与详细机理的计算结果及实验值进行了比较。结果表明简化机理与详细机理吻合较好，简化机理的规模和计算时间有所减少。     

模式预测法应用于铁路噪声的预测研究

伴随新建铁路、既有线增建二线、电气化改造等项目的大规模建设,围绕铁路建设、运营由来已久的铁路噪声污染和扰民的问题却更为突出。根据铁路噪声的传播特性,合理地选取了一种噪声预测方法,即模式预测法作为铁路噪声预测方法,并重点介绍了噪声模式法的理论依据、计算公式和边界条件。以我国中西部地区具有代表性的铁路干线之一作为研究对象,分析讨论由于工程规模、线路质量、列车速度、运输组织的变化,引起的铁路噪声对沿线声环境的影响,定量给出了典型区段距铁路外轨中心线30m、60m、120m处的昼夜间等效连续声级值。通过对噪声贡献值与声环境适应性分析,定性描述铁路噪声对周边环境产生的影响,研究成果为进一步有效控制铁路噪声污染、合理划分工程沿线土地利用功能提供有力依据。