模拟电梯运行中对正常成年人中耳功能的影响

目的观察正常成年人在模拟电梯运行中听力和鼓室压力的改变。方法选取听力和鼓室压力正常的受试者20例,即单耳40耳,评估其于50s改变密闭模拟电梯容器压力低于正常大气压2kPa、50s改变密闭容器压力低于正常大气压4kPa、以及压力恢复至正常水平时,言语频率500、1000、2000Hz的纯音听阈,鼓室压值和声阻抗曲线图形形态,以及鼓膜形态。结果当大气压低于正常值2kPa时,受试者言语频率的纯音听阈显著提高(均P<0.01),鼓室压力值发生显著改变(P<0.05);当大气压低于正常值4kPa时,受试者500、2000Hz的纯音听阈显著提高(P<0.01和P<0.05),鼓室压力值发生显著改变(P<0.01)。不同气压速率中的声阻抗曲线基本保持与正常大气压一致的A型曲线,极个别受试者出现C型曲线,无统计学意义。"2kPa/50s"和"4kPa/50s"两种情况下,鼓膜产生内陷或略内陷的发生率分别为15%和47.5%。结论高速电梯上升和下降过程中,周围环境大气压低于正常大气压时,乘坐者听力可发生一定程度地下降并造成鼓室负压。如果电梯的运行距离确定,则电梯的运行时间越短,即电梯的运行速度越大时,耳朵感觉越不舒适。

Influence of moving elevator on middle ear function of healthy adult

Objective To observe the changes of hearing level and tympanic pressure of healthy adult in moving elevator. MethodsTwenty volunteers (forty ears) with normal hearing level and tympanic pressure were enrolled and kept at airtight container. The inner pressure was changed to 2 kPa and 4 kPa below normal atmospheric pressure in 50 s and recovered to the normal pressure, the pure tune hearing threshold of 500, 1 000 and 2 000 Hz and tympanic pressure were measured, and acoustic impedance curve characteristic and tympanic membrane appearance were recorded at each time points. Results When the inner pressure reached 2 kPa below normal atmospheric pressure, the pure tune hearing thresholds ascended significantly (all P<0.01), and the tympanic pressure changed significantly(P<0.05). When the inner pressure reached 4 kPa below normal atmospheric pressure, the pure tune hearing threshold of 500 and 2 000 Hz ascended significantly(P<0.01 and P<0.05), and the tympanic pressure changed significantly(P<0.01). Most of the acoustic impedance curve for different air pressure velocity exhibited A pattern, just like that for the normal air pressure, except for a few of C pattern. However, no significant difference was found. The prevalence of tympanic membrane invagination was 15% and 47.5% respectively for 2 kPa /50 s and 4 kPa/50 s. Conclusion Hearing level will be decreased and tympanic pressure will experience changes in high-speed elevator ascending and descending with surrounding atmospheric pressure lower than normal atmospheric pressure. When the running distance is fixed, the faster the elevator travels, the more discomfort the ear experiences.