Papsin Emily, Harrison Adrienne L, Carraro Mattia, Harrison Robert V
Auditory Science Laboratory, Neuroscience and Mental Health Program, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8.
Auditory Science Laboratory, Neuroscience and Mental Health Program, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8 ; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada M5S 1A1.
Int J Otolaryngol. 2014;2014:248187. doi: 10.1155/2014/248187. Epub 2014 Jan 12.
Newborn hearing screening is an established healthcare standard in many countries and testing is feasible using otoacoustic emission (OAE) recording. It is well documented that OAEs can be suppressed by acoustic stimulation of the ear contralateral to the test ear. In clinical otoacoustic emission testing carried out in a sound attenuating booth, ambient noise levels are low such that the efferent system is not activated. However in newborn hearing screening, OAEs are often recorded in hospital or clinic environments, where ambient noise levels can be 60-70 dB SPL. Thus, results in the test ear can be influenced by ambient noise stimulating the opposite ear. Surprisingly, in hearing screening protocols there are no recommendations for avoiding contralateral suppression, that is, protecting the opposite ear from noise by blocking the ear canal. In the present study we have compared transient evoked and distortion product OAEs measured with and without contralateral ear plugging, in environmental settings with ambient noise levels <25 dB SPL, 45 dB SPL, and 55 dB SPL. We found out that without contralateral ear occlusion, ambient noise levels above 55 dB SPL can significantly attenuate OAE signals. We strongly suggest contralateral ear occlusion in OAE based hearing screening in noisy environments.
新生儿听力筛查在许多国家已成为一项既定的医疗保健标准，并且使用耳声发射（OAE）记录进行测试是可行的。有充分的文献记载，对测试耳对侧的耳朵进行声刺激可以抑制耳声发射。在隔音室中进行的临床耳声发射测试中，环境噪声水平较低，因此传出系统不会被激活。然而，在新生儿听力筛查中，耳声发射通常是在医院或诊所环境中记录的，那里的环境噪声水平可能为60-70 dB SPL。因此，测试耳的结果可能会受到刺激对侧耳朵的环境噪声的影响。令人惊讶的是，在听力筛查方案中，没有关于避免对侧抑制的建议，即通过堵塞耳道来保护对侧耳朵免受噪声影响。在本研究中，我们比较了在环境噪声水平<25 dB SPL、45 dB SPL和55 dB SPL的情况下，在对侧耳朵堵塞和不堵塞时测量的瞬态诱发耳声发射和畸变产物耳声发射。我们发现，在没有对侧耳朵堵塞的情况下，高于55 dB SPL的环境噪声水平会显著衰减耳声发射信号。我们强烈建议在嘈杂环境中基于耳声发射的听力筛查中进行对侧耳朵堵塞。
