Bicciolo G, Ruscito P, Rizzo S, Frenguelli A
Clinica Otorinolaringoiatrica, Università degli Studi di Perugia, Sede di Terni.
Acta Otorhinolaryngol Ital. 1993 Nov-Dec;13(6):505-15.
The Authors evaluated patterns of click-evoked otoacoustic emissions (EOE) in a group of 184 patients exposed to noise in their working environment. The aim of the study was to detect changes in EOE patterns in this group compared to the EOE of healthy subjects. The clinical history of each subject was recorded and otoscopy, pure tone audiogram and impedance tests (tympanometry, stapedial reflex threshold) were carried out in all patients. Noise-induced hearing loss found in 97 patients, unilateral sensorineural hearing loss in 17, other hearing disorders in 24 and normal auditory threshold in 46. EOE recording was carried out in the group of patients with noise-induced hearing loss (97), in the group with normal threshold (46) and in a control group of 15 healthy subjects. EOE recording was obtained using the ILO 88 Otodynamic Analyzer. We introduce a probe into the external ear canal using a non-linear click stimulus (intensity at approximately 85 dB spl) at a 20/sec. rate with a 20 msec. window. Normal EOE were found in the control group. Abnormal EOE were found in 79 cases (81%) of the noise-induced hearing loss group, and in 22 (48%) of the normal threshold group. These data show that noise-exposed subjects have alterations of EOE such as threshold shift missing frequency bands, even in absence of an auditory threshold shift. When EOE were present, the frequency spectrum often showed lack of emissions at high frequencies. This study confirms that cochlear exposure to noise may produce significant alterations of EOE and that this test may be considered highly sensitive in detecting early cochlear damage in chronic acoustic trauma. Therefore, EOE may be used in screening and follow-up of high risk populations such as noise-exposed subjects.
作者评估了184名在工作环境中接触噪声的患者的瞬态诱发耳声发射（EOE）模式。该研究的目的是检测该组患者与健康受试者的EOE模式相比的变化。记录了每个受试者的临床病史，并对所有患者进行了耳镜检查、纯音听力图和阻抗测试（鼓室图、镫骨肌反射阈值）。97名患者发现噪声性听力损失，17名患者为单侧感音神经性听力损失，24名患者有其他听力障碍，46名患者听觉阈值正常。对噪声性听力损失组（97名）、阈值正常组（46名）和15名健康受试者的对照组进行了EOE记录。使用ILO 88耳动态分析仪进行EOE记录。我们以20次/秒的速率，使用非线性瞬态刺激（强度约为85 dB声压级），在20毫秒的窗口内将探头插入外耳道。对照组中发现正常的EOE。噪声性听力损失组的79例（81%）和正常阈值组的22例（48%）发现异常EOE。这些数据表明，即使在没有听觉阈值偏移的情况下，接触噪声的受试者也存在EOE改变，如阈值偏移、频带缺失。当存在EOE时，频谱通常显示高频处缺乏发射。本研究证实，耳蜗暴露于噪声可能会导致EOE的显著改变，并且该测试在检测慢性声创伤中的早期耳蜗损伤方面可能被认为具有高度敏感性。因此，EOE可用于筛查和随访高风险人群，如接触噪声的受试者。
