对工业噪声致听力损伤的临床研究

目的:对噪声暴露工人0.5 kHz～16 kHz畸变产物耳声发射(DPOAE)和扩展高频测听进行研究.探讨工业噪声对作业人员听功能的影响,以期早期发现,早期干预.方法:用精密积分声级计记录北京人民机器厂机加工车间噪声强度及频谱分布,对42例耳科正常人和20例噪声暴露工人进行0.5 kHz～16 kHz DPOAE、常频纯音测听(0.5 kHz～8 kHz)及扩展高频测听(9 kHz～16 kHz)检查,比较DPOAE和纯音测听的结果.结果:生产车间噪声强度为87 dB～95 dB SPL(A),噪声频谱以 0.5 kHz～2 kHz为主.噪声暴露工人纯音听阈在6 kHz处和扩展高频区升高明显,DPOAE幅值在4 、6 kHz和11.2 kHz处较正常组明显下降,而在12.5 、14 、16 kHz三个频率二组几无差异.随着暴露噪声中的工龄延长,噪声暴露工人纯音听阈逐渐升高,DPOAE幅值逐渐降低.结论:长期暴露在工业噪声下可引起作业工人噪声性听力损失,且暴露时间对听力的影响具有累积作用.常频DPOAE检查及扩展高频测听均可用于噪声性聋的早期诊断和监测.DPOAE的产生部位和机制尚需深入研究.

Clinical study on hearing damage in industrical noise exposure workers

Objective: To investigate the result of distortion product otoacoustic emissions(DPOAE)and expanded high frequency audiometry in noise exposure workers. Methods: DPOAE, conventional pure tone audiometry and expanded high frequency audiometry were examined in 42 young adults with normal hearing and 20 noise exposure workers. DPOAE amplitudes, conventional pure tone hearing thresholds and expanded high frequency hearing thresholds were compared. Results: In noise exposure workers against young adults with normal hearing, the pure tone hearing thresholds at 6 kHz and expanded high frequency area declined significantly,DPOAE amplitudes at frequency from 4 to 6 kHz and 11.2 kHz declined obviowly too,but there existed no significantly difference at frequency from 12.5 to 16 kHz between the two groups. Conclusion:DPOAE is potential implement to early diagnose and detect noise-induced deafness. The originated area and mechanism of DPOAE should be solved by further studies.