Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
Int J Audiol. 2009;48(9):655-60. doi: 10.1080/14992020903012481.
This longitudinal study investigated how chronic gunshot noise exposure affects cochlear and saccular function in police officers who engaged in regular target shooting practice using dual protection (ear plugs plus earmuffs) for >10 years. In 1997, 20 male police officers underwent audiometry before and two weeks after shooting. Twelve of the original subjects were re-examined by audiometry coupled with vestibular evoked myogenic potential (VEMP) test in 2007. Significant deterioration of mean hearing thresholds at frequencies of 500 Hz through 4000 Hz was noted ten years later, affecting both ears. However, only the frequencies of 4000 and 6000 Hz on the left ear revealed significant difference in mean hearing thresholds compared with healthy controls. Abnormal VEMP responses were evident in nine police officers (75%), including absent VEMPs 7 and delayed VEMPs 2. In conclusion, deterioration to hearing may occur after long term exposure to gunshots, even when double hearing protection is used. Further study is in progress regarding how to preserve both cochlear and saccular function during long term gunshot exposure.
本纵向研究调查了长期接触枪声如何影响长期使用双耳耳塞和耳罩进行常规射击训练的警察的耳蜗和囊斑功能。1997 年，20 名男性警察在射击前和射击后两周接受了听力测试。12 名最初的受试者于 2007 年通过听力测试和前庭诱发肌源性电位 (VEMP) 测试重新检查。十年后，双耳的 500Hz 至 4000Hz 频率的平均听力阈值明显恶化。然而，与健康对照组相比，左耳的 4000Hz 和 6000Hz 频率的平均听力阈值仅显示出显著差异。9 名警察（75%）出现异常 VEMP 反应，包括 VEMPs7 缺失和 VEMPs2 延迟。总之，即使使用双重听力保护，长期接触枪声也可能导致听力下降。目前正在进行进一步的研究，以探讨如何在长期接触枪声时保护耳蜗和囊斑功能。
