Wallace M S, Ashman M N, Matjasko M J
Department of Anesthesiology, University of California, San Diego, La Jolla 92093-0818.
Anesthesiology. 1994 Jul;81(1):13-28. doi: 10.1097/00000542-199407000-00005.
With rapid technological advances in anesthesiology, we are acquiring an ever increasing number of auditory alarm systems in the operating room the value of which depend on the hearing acuity of the anesthesiologist monitoring the patient. Presbycusis, the effect of aging on the auditory system, characteristically results in a bilaterally symmetric neurosensory high-frequency hearing loss ( > 2,000 Hz). In this study we attempt to assess the impact of this common hearing disorder on alarm detection.
We measured air conduction hearing acuities of 188 anesthesiologists who volunteered to participate. Subjects were divided into six age groups (25-34, 35-44, 45-54, 55-64, and > 75 yr of age). Abnormal audiograms were compared to the intensity and frequency of alarms in our operating room to determine which alarms were out of hearing range. Subjects with a history of chronic or excessive noise exposure were excluded from the study. The median hearing threshold for each age group of study subjects was compared to the median hearing threshold of similar age groups in the general population.
Overall, 66% of the subjects had an abnormal audiogram, and 7% had one or more alarm intensities less than their detectability threshold (14% unilateral, 86% bilateral). Median hearing threshold was worse than the general population for men and women less than 55 yr of age. Hearing acuity worse than the general population occurred at the lower frequencies while acuity at the higher frequencies was equal or slightly better. However, inability to hear alarms occurred only with those alarms that have frequencies of 4,000 Hz or greater.
Although high-frequency hearing acuity of individuals in our study was better than that of the general population, hearing deficits at high frequencies were of the magnitude to interfere with alarm detection. Also background noise levels vary greatly in different operating rooms. These two problems create a hindrance to alarm detection for certain anesthesiologists. From our data we conclude that the aging human ear may not be capable of accurately detecting some auditory alarms in the operating room. Alarm design should consider hearing acuity because high-frequency alarms may go undetected.
随着麻醉学技术的飞速发展，我们在手术室配备了越来越多的听觉警报系统，而这些系统的价值取决于监测患者的麻醉医生的听力敏锐度。老年性聋是衰老对听觉系统的影响，其特征是导致双侧对称的神经感觉性高频听力损失（>2000Hz）。在本研究中，我们试图评估这种常见听力障碍对警报检测的影响。
我们测量了188名自愿参与的麻醉医生的气导听力敏锐度。受试者被分为六个年龄组（25 - 34岁、35 - 44岁、45 - 54岁、55 - 64岁和>75岁）。将异常听力图与我们手术室中警报的强度和频率进行比较，以确定哪些警报超出了听力范围。有慢性或过度噪声暴露史的受试者被排除在研究之外。将研究受试者各年龄组的听力阈值中位数与一般人群中相似年龄组的听力阈值中位数进行比较。
总体而言，66%的受试者听力图异常，7%的受试者有一个或多个警报强度低于其可检测阈值（单侧14%，双侧86%）。年龄小于55岁的男性和女性的听力阈值中位数比一般人群更差。在较低频率时听力敏锐度比一般人群差，而在较高频率时听力敏锐度相同或略好。然而，只有频率为4000Hz或更高的警报才会出现听不见的情况。
虽然我们研究中个体的高频听力敏锐度优于一般人群，但高频听力缺陷的程度足以干扰警报检测。此外，不同手术室的背景噪声水平差异很大。这两个问题给某些麻醉医生的警报检测造成了障碍。根据我们的数据，我们得出结论，衰老的人耳可能无法准确检测手术室中的某些听觉警报。警报设计应考虑听力敏锐度，因为高频警报可能无法被检测到。
