Job A, Hamery P, De Mezzo S, Fialaire J-C, Roux A, Untereiner M, Cardinale F, Michel H, Klein C, Belcourt B
a Institut de Recherche Biomédicale des Armées (IRBA) , Brétigny-sur-Orge , France .
b INSERM U836, GIN , Grenoble , France .
Int J Audiol. 2016;55(1):30-7. doi: 10.3109/14992027.2015.1070967. Epub 2015 Sep 2.
We tested middle-ear functioning in humans following intense exposure to noise. Noise generated by small caliber firearms was thought to have no effect on the middle-ear.
A cross-over design. We measured middle-ear impedance, acoustic reflex, distortion product otoacoustic emissions (DPOAEs), and transient evoked otoacoustic emissions (TEOAEs) before and after practice rounds performed twice per day.
Fifty-nine soldiers equipped with earplugs undergoing regular training for a special mission. The mean noise exposure (LAeq8h) was estimated to be 106 ±1 dB SPL.
Impedancemetry revealed a significant increase in the compliance and gradient of the tympano-ossicular chain after impulse noise exposure in the right and left ears. Acoustic reflex reactivity did not show a significant change. DPOAEs and TEOAEs were slightly decreased at 2 kHz, and showed a marked asymmetry in disfavor of the left ear. In soldiers with initial high reactivity of acoustic reflex, increased compliance was associated with a significant decrease in left TEOAEs at 1.5 and 2 kHz.
Our results suggest that the use of small-caliber firearms, even while wearing earplugs, affects middle-ear function and may play a role in the early stage of auditory fatigue encompassing tinnitus.
我们测试了人类在强烈噪声暴露后的中耳功能。小口径火器产生的噪声被认为对中耳没有影响。
交叉设计。我们在每天进行两轮练习前后测量中耳阻抗、声反射、畸变产物耳声发射（DPOAE）和瞬态诱发耳声发射（TEOAE）。
59名配备耳塞并正在接受特殊任务常规训练的士兵。平均噪声暴露（LAeq8h）估计为106±1 dB SPL。
阻抗测量显示，在脉冲噪声暴露后，左右耳的鼓室-听骨链顺应性和梯度显著增加。声反射反应性未显示出显著变化。DPOAE和TEOAE在2 kHz时略有下降，并且明显不对称，左耳更差。在声反射初始反应性较高的士兵中，顺应性增加与1.5 kHz和2 kHz时左耳TEOAE显著下降相关。
我们的结果表明，即使佩戴耳塞，使用小口径火器也会影响中耳功能，并且可能在包括耳鸣在内的听觉疲劳早期阶段起作用。
