不同强度窄带噪声暴露对豚鼠畸变产物耳声发射的影响

Effects of DPOAE on guinea pigs exposed to narrow band noise of different intensity

目的探讨不同强度窄带噪声暴露对豚鼠畸变产物耳声发射（DPOAE）的影响。方法雄性健康豚鼠60只，随机均分为3组，105dBA组、110dBA组和115dBA组，暴露时间均为3h，实验均采用窄带噪声，中心频率4000Hz，带宽1000Hz。噪声暴露前2d及暴露后15min，采用smart OAE测听系统检测各组豚鼠DPOAE。结果随着噪声暴露量增加，豚鼠各畸变频率的DPOAE幅值及通过率均呈减少的趋势。其中，105dBA组和110dBA组在畸变频率1409Hz处，105dBA组和115dBA组在畸变频率499、704、1003、1409Hz处，噪声暴露后的DPOAE幅值和通过率差异有统计学意义（P〈0．05）。结论4000Hz窄带噪声暴露后DPOAE改变首先出现在高频，噪声强度增加可使听觉损伤由高频向低频延展。

Objective To study the effect of distortion product otoacoustic emission （DPOAE） on guinea pigs exposed to narrow hand noise of different intensity. Methods Sixty healthy male guinea pigs were randomly divided into 3 groups： the 105 dBA group,the 110 dBA group and the 115 dBA group. The duration of exposure for all the groups was 3 hours and noise spectrum was narrow - band, with a mid - frequency of 4 000Hz and hand-width of 1000 Hz. Two days before and 15 minutes after noise exposure,DPOAE of guinea pigs was measured by means of Smart OAE Hearing Test System. Results With increased intensity in noise exposure,DPOAE amplitude and throughput of guinea pigs at all the distortion frequencies showed a decreased tendency. For the 105 dBA group and the 110 dBA group at the distortion frequency of 1 409 Hz,and for the 105 dBA group and the 115 dBA group at frequencies of 499 Hz,704 Hz, 1 003 Hz, and 1 409 Hz, the difference in DPOAE amplitude and throughput after exposure all had statistically significance （ P 〈 0.05 ）. Conclusions Following exposure to 4 000Hz narrow band noise, DPOAE began to change at high frequencies and hearing damage extended from higher frequency to lower frequencies as noise level increased.