Xu Z M, De Vel E, Vinck B, Van Cauwenberge P
Department of Otolaryngology, University Hospital Ghent, Belgium.
Eur Arch Otorhinolaryngol. 1996;253(4-5):222-6. doi: 10.1007/BF00171131.
In this study 23 patients with noise-induced hearing loss (NIHL) referred for medico-legal evaluation and a group of 18 cases with Ménière's disease were evaluated audiologically using the middle-latency response (MLR). Cross-correlation functions were used to assess precisely MLR thresholds in low and middle frequencies. Cross-correlation data obtained from suprathreshold levels to below threshold levels were compared with the normal limits of parameters found at threshold levels, allowing us to determine the true MLR threshold. Our results revealed that this MLR threshold and visual detection thresholds were different in 18% of both the NIHL and Ménière's disease groups. In this population the true MLR threshold was greater by 5 dB. These findings demonstrated that cross-correlation functions can enhance the sensitivity of the definition of the MLR threshold. True MLR thresholds were compared with subjective pure-tone audiometric (PTA) thresholds at the same frequencies (0.5, 1 and 2 kHz). The true MLR threshold and PTA threshold were in agreement within 10 dB in 91% of the NIHL group and all of the Ménière's disease group. The PTA threshold was greater by 15 dB or more in the remaining NIHL group. If a criterion of 15 dB discrepancy indicates non-organic hearing loss, it can be inferred that 9% of an NIHL population referred for medico-legal evaluation is exaggerating subjective audiometric thresholds.
在本研究中，对23例因噪声性听力损失（NIHL）前来进行法医学评估的患者以及18例梅尼埃病患者进行了中潜伏期反应（MLR）的听力学评估。使用互相关函数精确评估低频和中频的MLR阈值。将从阈上水平到阈下水平获得的互相关数据与阈水平时发现的参数正常限值进行比较，从而使我们能够确定真正的MLR阈值。我们的结果显示，在NIHL组和梅尼埃病组中，均有18%的患者其MLR阈值与视觉检测阈值不同。在这一人群中，真正的MLR阈值高5 dB。这些发现表明，互相关函数可以提高MLR阈值定义的敏感性。将真正的MLR阈值与相同频率（0.5、1和2 kHz）下的主观纯音听力计（PTA）阈值进行比较。在NIHL组的91%以及所有梅尼埃病组中，真正的MLR阈值与PTA阈值在10 dB范围内相符。在其余的NIHL组中，PTA阈值高15 dB或更多。如果以15 dB的差异作为非器质性听力损失的标准，可以推断，前来进行法医学评估的NIHL人群中有9%夸大了主观听力阈值。
