Ruth R A, Tucci D L, Nilo E R
Ear Hear. 1982 Jan-Feb;3(1):39-41. doi: 10.1097/00003446-198201000-00009.
Acoustic reflex (AR) threshold and growth were measured in one ear for each of 20 normal-hearing individuals as pressure in the ear canal was varied between +/- 120 mm of H2O. These same parameters were studied in 10 of the subjects after disruption of the probe seal. Activating stimuli for AR threshold measures were 500, 1000, 2000, and 4000 Hz tones and broadband noise. The AR growth function was generated by a 500 Hz tone. As ear canal pressure was increased or decreased relative to the point of maximal compliance, systematic increases in AR threshold were observed for all activating stimuli. These mean pressure effects were relatively small (4 to 8 dB) and were essentially independent of stimulus composition. The ear canal pressure variations had no effect on the relative difference between tone and broadband noise AR thresholds. Absence of an airtight seal had a negligible effect on AR threshold. Growth of the AR was significantly altered by application of a relatively mild positive or negative canal pressure. Absence of a probe seal which had no effect on AR threshold was found to significantly reduce magnitude of the AR. These findings indicate that caution should be exercised during the measurement of AR growth to ensure both proper maintenance of desired canal pressure and canal-probe coupling.
在20名听力正常的个体中，当耳道压力在±120毫米水柱之间变化时，测量了每只耳朵的声反射（AR）阈值和增长情况。在破坏探头密封后，对其中10名受试者进行了相同参数的研究。AR阈值测量的激活刺激为500、1000、2000和4000赫兹的纯音以及宽带噪声。AR增长函数由500赫兹的纯音产生。相对于最大顺应点，当耳道压力增加或降低时，所有激活刺激的AR阈值均出现系统性升高。这些平均压力效应相对较小（4至8分贝），且基本与刺激成分无关。耳道压力变化对纯音和宽带噪声AR阈值之间的相对差异没有影响。密封不严对AR阈值的影响可忽略不计。施加相对温和的正或负耳道压力会显著改变AR的增长。发现对AR阈值无影响的探头密封缺失会显著降低AR的幅度。这些发现表明，在测量AR增长时应谨慎操作，以确保所需耳道压力和耳道 - 探头耦合的适当维持。
