噪声适应性暴露对人听力保护作用的初步探讨

目的：观察适应性噪声暴露对听力的保护作用。方法：将44名青年志愿者随机分为4组（每组11人，男6人，女5人），其中2组为适应性暴露组，另2组为直接暴露组，适应性暴露1组和2组先暴露于中心频率为0．5kHz，声压级为95dB SPL的一个倍频程噪声，每天6h，连续暴露10d，休息2d后，再连续3d分别暴露于声压级为105dB的一个倍频程噪声（2．5h/d)和白噪声（0．5h/d)，而直接暴露的两组预先不进行适应性暴露，直接暴露于105dB的一个倍频程噪声和白噪声，连续3d,每天2．5h，以暂时性听阈位移（TTS）作为观察指标。结果：在高噪声暴露过程中，适应性暴露组与直接暴露组相比，除8kHz外，TTS在各个频率上差异均有显著性，结论：经过一定强度噪声的适应性暴露后，能够减轻更高强度噪声所致听力损伤的程度。

Study on Conservative Effect of Noise Conditioning on Acoustic System of Human Being

Objective To study the conservative effect of noise conditioning on acoustic system of human being.Methods 44 young volunteers were randomly and equally divided into four groups with 6 males and 5 females in each group.Two groups were taken as noise conditioning groups,and the other two as directly exposed groups exposed directly to damaging noise.Conditioning group 1 and 2 were subjected to 95 dB SPL OBN(centered at 0^5 kHz,6 h/d)for 10 days.After an intermittence of 2 days,both groups were exposed to 105 dB SPL OBN(2^5 h/d)and white noise(0^5 h/d) for 3 days,respectively.The directly exposed groups were exposed to intense sound(105 dB SPL)without conditioning exposure.Temporary threshold shift(TTS)was tested as the index.Results The values of TTS were significantly different between conditioning groups and directly exposed groups at all frequency except 8 kHz.Conclusions After noise conditioning,the acoustic system acquired resistance to high intensity damaging noise.