脉冲噪声持续时间对听觉损伤程度影响的研究

实验观察了脉冲噪声长持续时间引起的听觉损伤与短时间引起的听觉损伤是否有明显区别，为修订有关卫生标准和听力保护提供依据。声暴露豚鼠分为５组，接受由同一声源产生的、峰值声压级为１６０ｄＢ、脉冲发数１０发、持续时间分别为５０ｍｓ、１００ｍｓ、２００ｍｓ、４００ｍｓ、和８００ｍｓ的脉冲噪声暴露，并与对照组比较，观察听觉损伤程度的差别。结果表明，暴露后７ｈ起各组听力均开始恢复，但到１４ｄ仍遗留有听力损失。听力损失随着持续时间的增加而加重，组间差异显著。耳蜗毛细胞的缺失以第２、３圈为甚，缺失率和缺失范围也随持续时间的增加而增大。建议修订有关脉冲噪声安全标准时应考虑１００ｍｓ以上时间的作用。     

高强度脉冲噪声发生器及其应用

目的为了研究脉冲噪声对机体的生物效应，我们研制了高强度可调脉冲噪声发生器，它由脉冲控制器、固态继电器、电磁阀和气流扬声器等几部分组成。方法利用该装置进行了脉冲噪声不同宽度对豚鼠听觉系统损伤程度影响的研究。结果高强度可调脉冲噪声发生器具有体积小、使用方便、几个参数可调等优点。结论试验显示，动物的听力损失随着脉冲宽度的增加而加重，组间差异显著。耳蜗毛细胞的缺失范围和缺失率也随脉冲宽度的增加而增大。建议在制订脉冲噪声卫生标准时应考虑长脉宽（如１００ｍｓ以上）的不同宽度的作用。     

常规兵器发射或爆炸时脉冲噪声和冲击波对人员听器损伤的安全限值

目的：为了预防武器发射时对人员听觉器官的损害,特制定本标准。方法：在大量常规兵器发射试验所获参数的基础上,并参考国内外有关文献编制而成。结果：提出了所制定的１．５ｍｓ＜ＴＡ≤１００ｍｓ的武器及０．２５ｍｓ≤ＴＡ≤１．５ｍｓ的武器脉冲噪声与冲击波对人员听器损伤安全限值,并提出了标准的适用范围。结论：本标准适用于暴露在常规兵器发射或爆炸所产生的脉冲噪声与冲击波中的无防护人员,常规兵器的科研生产也可参照使用。     

苯异丙腺苷(R-PIA)抗脉冲噪声所致内耳损伤的实验研究

目的 研究在脉立足点器材怕环境下苯异丙腺苷（Ｒ－Ｎ－６０ｐｈｅｎｙｌｉｓｏｐｒｏｐｙｌａｄｅｎｏｓｉｎｅ,Ｒ－ＰＩＡ）对听觉系统损伤的预防和保护作用。方法 ６只灰鼠（ｃｈｎｃｈｉｌｌａｓ）在暴露于１００个１５０ｄＢ ＳＰＬ脉冲噪声前２ｈ在其右耳用药（Ｒ－ＰＩＡ０．１ｍｍｏｌ／Ｌ,３０μｌ）。脉冲噪声是模拟Ｍ－１６来福枪而成。结果 用Ｒ－ＰＩＡ药物的右耳在噪声暴露后,其暂时性阈移（ＩＴＳ）和卞久睡阈     

常规兵器发射或爆炸时脉冲噪声和冲击波对人员听器损伤的安 …

目的：为了预防武器发射时对人员听觉器官的损害,特别定本标准。方法：在在量常规兵器发射试验所获参数的基础上,并参考国内外有关文献编制而成。结果：提出所制定的１．５ｍｓ〈ＴＡ≤１００ｍｓ的武器及０．２５ｍｓＴＡ≤１．５ｍｓ的武器脉冲噪声与冲击波对人员听器损伤安全限值,并提出了标准适用范围。结论：本标准适用于暴露在常规兵器发射或爆炸所产生的脉冲与冲击波中的无防护人员,常规丘器的科研生产也可参照使用。     

脉冲噪声损伤听觉系统的药物预防研究

目的 研究在脉冲噪声环境下药物Ｒ－Ｎ６－ｐｈｅｎｙｌｉｓｏｐｒｏｐｙｌａｄｅｎｏｓｉｎｅ（Ｒ－ＰＩＡ）对听觉系统损伤的预防作用。方法 ６只美洲大鼠（ｃｈｉｎｃｈｉｌｌａｓ）在暴露于１００个１５０ｄＢ（ｐｅａｋ,ＳＰＬ）脉冲噪声前２小时在其右耳用药（Ｒ－ＰＩＡ）（０．１ｍｍｏｌ／Ｌ ３０μｌ）。脉冲噪声是模拟Ｍ－６来福枪而成。结果 用Ｒ－ＰＩＡ药物的右耳其暂时性阈移（ＴＴＳ）和永久性阈移（ＰＴＳ）比     

冲锋枪脉冲噪声对豚鼠听觉损伤的影响

为了研究轻武器噪声对听觉损伤的影响，观察了冲锋枪射击时产生的脉冲噪声对豚鼠听力和耳蜗毛细胞的作用。结果表明，各组动物经受峰值１５５，１６０，１６５和１７０ｄＢ各５发的脉冲噪声后４８小时，听力损失分别为７．０，１５．０，２２．７，和２７．５ｄＢ。２周后除了１５５ｄＢ组外，大多数动物的听力未恢复到正常水平。耳蜗毛细胞损伤以外毛细胞为主，其缺失率随噪声暴露强度的增加而增多。１５５ｄＢ组损伤轻微，缺失率为６．９％，１７０ｄＢ组损伤最重，缺失率高达３０．８％，而且内毛细胞也出现了损伤。实验结果同《常规武器发射或爆炸时压力波对人体作用的安全标准》（ＧＪＢ２－８２）相对照，发现在安全标准限值之内的动物亦出现了不同程度的损伤。提示该标准不够安全，可能不适合轻武器噪声的暴露条件。     

两个参数评价汽车制造业脉冲噪声作业达标率的比较

目的为了能够精确地检测出脉冲噪声作业工人实际接触的噪声声压级并对之进行客观的评价，更好地保护工人身体健康。方法对某大型汽车制造企业的195个脉冲噪声作业岗位的脉冲噪声分别就峰值声压级和8h等效A声级2种参数进行检测和评价。结果当接触频次〉10000次／d时，2种检测参数评价结果差异没有统计学意义；当接触频次〈100和100～10000次／d时，2种检测参数评价结果差异有统计学意义。结论建议在不同声压级和频次的工业脉冲噪声同时存在的环境下，对脉冲噪声的检测评价应综合考虑本底噪声值，日接触频次和脉宽等参数，或分析现场情况，准确确定检测参数进行检测评价。     

脉冲噪声致豚鼠听觉损伤观察

为观察脉冲噪声暴露期间的听阈位位移和暴露后听阈的恢复及毛细胞缺失情况，将１０只豚鼠暴露于１２５ｄＢｐｅａｋＳＰＬ脉冲噪声５天，同时将１０只豚鼠暴露于１１０ｄＢＳＰＬ稳态噪和为参照。测定每天暴露后即测及全部暴露停止后２ｈ、８ｈ、２４ｈ、２４０ｈ、３６０ｈ的听阈位移，观察２周后耳蜗毛细胞缺失率。结果显示：（１）５天暴露期间两组动物的听阈位移在某一相对稳定的水下上下波动；（２）暴露脉冲噪声后５天动物中有     

脉冲噪声与持续噪声对工人听力损害的比较——试论以Leq(A)来评价工业脉冲噪声

脉冲噪声广泛存在于工业生产中。脉冲噪声与持续噪声性质不同。评价脉冲噪声的主要指标为脉冲峰值、持续时间(脉宽)、脉冲次数。测定脉冲噪声需要一套专门的测定分析仪器,目前我国多数劳动卫生机构尚不具备这种手段。另外我国现在尚未制定工业脉冲噪声的卫生标准,这给我们对工业脉冲噪声作业环境的卫生学     

用等效连续A声级评价不同类型噪声的探讨

目的：探索能否用等效连续Ａ声级（ＬＡｅｑ）来评价不同类型的噪声。方法：以豚鼠为对象,用ＬＡｅｑ相同的脉冲噪声、稳态噪声或以上两者的复合噪声连续暴露５ｄ,每天７ｈ,观察分析听力损失和恢复过程以及耳蜗毛细胞损伤程度的差别。结果：各组动物听力损失的程度不同相等,即脉冲噪声比复合噪声所致的损伤稍重,复合噪声又比稳态噪声造成的损伤稍重。毛细胞缺失情况各组差别不大,但也有脉冲噪声比复合噪声重,复合噪声比稳态噪     

Is the aged rat ear more susceptible to noise or styrene damage than the young ear?

Noise- and styrene-induced hearing and hair cell loss were studied in young (3 months) and aged (24-26 months) Long-Evans rats. The animals were exposed 6 h/d, 5 d/w for 4 weeks to (a) broadband noise centered at 8 kHz (92 or 97dB SPL), or b) styrene (700 ppm). Auditory sensitivity was tested by recording evoked potentials from the inferior colliculus. Histological analyses of the organ of Corti, stria vascularis, and the spiral ganglions were also performed. Aged controls showed outer hair cell (OHC) loss at the basal and apical regions of the organ of Corti, and an increase in pigmentation concomitant to a decrease in vascularization of the stria vascularis, along with elevated thresholds relative to young controls. The 92-dB noise caused similar threshold shifts in both age groups, whereas the 97-dB noise caused more threshold shifts in the aged group compared to the young group. Recovery of the hearing thresholds depended both on the intensity of the noise and on the age of the animals. Aged rats had minimal hair cell loss as a result of styrene exposure, whereas young animals showed significant OHC loss, particularly in third row. Despite significant loss of OHCs, the young subjects showed styrene-induced threshold shifts only at high frequencies. In summary, the data show that : (a) there is an influence of age on both noise-induced and styrene-induced threshold shift and hair cell loss in rats and (b) the cochlea appear to have a redundancy in the number of OHCs, thus threshold shift does not necessarily occur with significant OHC loss.     

用个体暴露评价脉冲噪声与稳态噪声所致高频听力损失的关系

目的用个体噪声暴露测量数据比较工业脉冲噪声与稳态噪声所致高频听力损失剂量反应关系的异同。方法1998至1999年,以32名接触脉冲噪声的机械制造工人和163名接触稳态噪声的纺织工人为观察对象,用噪声剂量计采集8h工作期间的噪声暴露数据,计算8h等效声级(LAeq.8h),并按等能量原理将LAeq.8h和噪声作业工龄合并为累积噪声暴露量(CNE)。用常规方法测量工人左右耳气导听阈,按GBZ492002对听阈做年龄性别校正,并诊断是否为高频听力损失。结果脉冲噪声组的CNE[(103.2±4.2)dB(A)·年]明显低于稳态噪声组[(110.6±6.0)dB(A)·年],脉冲噪声组高频听力损失患病率(68.8%)与稳态噪声组(65.0%)相似,分层分析和趋势卡方检验证实,两组CNE与高频听力损失患病率间均存在典型的剂量反应关系,差异有统计学意义;脉冲噪声100～104和105～109dB(A)·年两组的高频听力损失患病率(76.9%和90.9%)高出稳态噪声组(30.4%和50.0%)约1倍。logistic回归模型显示,脉冲噪声组CNE与高频听力损失患病率的剂量反应关系曲线与稳态噪声组相比出现曲线左移,斜率增大。结论采用个体噪声暴露数据计算时,在能量相同的情况下,脉冲噪声所致高频听力损失的危害大于稳态噪声。     

Effects of impulse noise and continuous steady state noise on hearing.

In this study the effects on hearing induced by occupational exposure to impulse noise were compared with those induced by exposure to continuous steady state noise. Three groups exposed to impulse noise, one group exposed to continuous steady state noise, and an unexposed control group were studied. The hearing thresholds of the groups were measured by a puretone audiometer three times in two workdays. None of the groups showed significant differences between the hearing thresholds measured in the morning, at midday, and in the afternoon. Group 1 with the shortest duration of exposure and group 2 with the intermediate duration of exposure to impulse noise had the highest thresholds at 6000 Hz in both ears. Group 3 with the longest duration of exposure to impulse noise had the highest thresholds asymmetrically, at 4000 Hz in the left ear and at 6000 Hz in the right ear. The group exposed to continuous steady state noise also had the highest thresholds asymmetrically, in the left ear at 6000 Hz. It was concluded that the longer the duration of exposure to impulse noise the wider the region of the frequencies that showed raised threshold shifts in both ears. Impulse noise seemed to produce permanent threshold shifts at 4000 and 6000 Hz after a shorter duration of exposure than continuous steady state noise.     

Temporal and speech processing skills in normal hearing individuals exposed to occupational noise

Prolonged exposure to high levels of occupational noise can cause damage to hair cells in the cochlea and result in permanent noise-induced cochlear hearing loss. Consequences of cochlear hearing loss on speech perception and psychophysical abilities have been well documented. Primary goal of this research was to explore temporal processing and speech perception Skills in individuals who are exposed to occupational noise of more than 80 dBA and not yet incurred clinically significant threshold shifts. Contribution of temporal processing skills to speech perception in adverse listening situation was also evaluated. A total of 118 participants took part in this research. Participants comprised three groups of train drivers in the age range of 30-40 (n= 13), 41 50 ( = 13), 41-50 (n = 9), and 51-60 (n = 6) years and their non-noise-exposed counterparts (n = 30 in each age group). Participants of all the groups including the train drivers had hearing sensitivity within 25 dB HL in the octave frequencies between 250 and 8 kHz. Temporal processing was evaluated using gap detection, modulation detection, and duration pattern tests. Speech recognition was tested in presence multi-talker babble at -5dB SNR. Differences between experimental and control groups were analyzed using ANOVA and independent sample t-tests. Results showed a trend of reduced temporal processing skills in individuals with noise exposure. These deficits were observed despite normal peripheral hearing sensitivity. Speech recognition scores in the presence of noise were also significantly poor in noise-exposed group. Furthermore, poor temporal processing skills partially accounted for the speech recognition difficulties exhibited by the noise-exposed individuals. These results suggest that noise can cause significant distortions in the processing of suprathreshold temporal cues which may add to difficulties in hearing in adverse listening conditions.     

噪声习服对听觉损伤保护作用

目的探讨噪声习服对听觉损伤的保护作用。方法取健康成年豚鼠40只，随机分为正常对照组、噪声习服组、噪声损伤暴露组和噪声习服后损伤暴露组。建立噪声习服实验动物模型。采用听觉电生理测试和耳蜗基底膜铺片的方法，分别测定听性脑干反应（ABR）阈值及毛细胞缺失率的变化。结果噪声习服暴露对其后强噪声损伤暴露引起的听力损失产生了13dB的保护作用。耳蜗基底膜铺片显示，本实验中暴露引起的毛细胞缺失较明显，习服后损伤暴露组与直接损伤的暴露组相比基底膜第Ⅰ、Ⅱ圈的毛细胞缺失减少。结论采用适宜的噪声暴露参数，噪声习服暴露可对其后强噪声损伤暴露引起的听力损失产生保护作用。噪声暴露引起的毛细胞形态学改变包括细胞缺失和非致死性细胞损伤。噪声习服暴露后减少其后强噪声损伤暴露引起的毛细胞缺失。     

脉冲与稳态噪声引起工人听力损伤的差异

对接触脉冲噪声和稳态噪声的７７１名工人调查发现，年龄性别校正后的高频听力损伤患病率为６０．４％、语频为５．４％。听力损伤患病率随噪声暴露的剂量增大而升高，有剂量—反应关系。接触脉冲噪声工人的高频听力损伤患病率（６２．４％，３４５／５５３）高于稳态噪声（５５．５％，１２１／２１８），但无显著差异；而语频听力损伤患病率（６．７％，３７／５５３）明显高于稳态噪声（２．３％，５／２１８）。脉冲噪声引起的听力损伤曲线出现左移，表明它对听觉系统的危险性高于稳态噪声。     

噪声作业对生产工人听力影响的调查与分析

本文对1083 名稳态噪声作业、135名脉冲噪声作业及467 名非噪声作业职工进行了听力检查,结果表明: 稳态噪声、脉冲噪声作业职工听力损伤发生率分别是47.8% 、65.9% , 听损检出率显著高于对照组 (8.1% ), P< 0.01; 脉冲组听损检出率显著高于稳态组(P< 0.01)。听力损伤检出率随噪声暴露水平、累积噪声暴露量及接噪工龄的增长而增高, 均表现为正相关关系 (r= 0.9211～0.9874, P< 0.05), 呈明显的剂量反应关系