Probst R, Harris F P
Department of Otorhinolaryngology, University of Basel, Switzerland.
J Acoust Soc Am. 1996 Jul;100(1):504-10. doi: 10.1121/1.415863.
Measurements of spontaneous and click-evoked otoacoustic emissions (OAEs) were used to classify listeners with normal hearing into one of two categories--those with spontaneous emissions (SOAEs) and high-level transiently evoked emissions (TEOAEs) in both ears (strong emissions) and those with no SOAEs and low-level TEOAEs in either ear (weak emissions). Just-noticeable differences (jnd's) in intensity for 1-kHz pure tones presented at either 60, 40, or 20 dB SL were determined for these two groups using a continuous pedestal technique. Mean jnd's for intensity for the two groups did not differ significantly. Intratest variability was compared and the group with strong emissions had significantly higher variability for presentation levels of 20 dB SL and lower variability at 60 dB SL. Additional testing of intensity jnd's was performed in individuals with strong emissions using pure tones 30 Hz lower than a targeted SOAE frequency. Large interindividual differences were present without a specific pattern. It is concluded that OAE activity level does not affect the mean jnd for intensity discrimination. Individuals with strong emissions have less variance when performing the test at higher levels and more variance for lower level stimuli than do individuals with weak emission characteristics. Because an ear's OAE characteristics can alter performance on psychoacoustic tasks, knowledge of such characteristics is desirable when psychoacoustic results are acquired and reported.
通过测量自发性耳声发射（SOAE）和瞬态诱发性耳声发射（TEOAEs），将听力正常的受试者分为两类：双耳均有自发性耳声发射（SOAE）和高水平瞬态诱发性耳声发射（TEOAEs）的受试者（强发射），以及双耳均无SOAE且TEOAEs水平较低的受试者（弱发射）。使用连续基座技术，针对这两组受试者，测定了在60、40或20 dB SL下呈现的1kHz纯音强度的最小可觉差（jnd）。两组受试者的强度平均jnd无显著差异。比较了测试内的变异性，结果显示，在20 dB SL的呈现水平下，强发射组的变异性显著更高，而在60 dB SL下，变异性更低。对强发射个体进行了额外测试，使用比目标SOAE频率低30 Hz的纯音测量强度jnd。个体间存在较大差异，且无特定模式。研究得出结论，耳声发射活动水平不影响强度辨别平均jnd。与弱发射特征个体相比，强发射个体在较高水平进行测试时变异性较小，而在较低水平刺激下变异性较大。由于耳朵的耳声发射特征可能会改变心理声学任务的表现，因此在获取和报告心理声学结果时，了解这些特征是很有必要的。
