McDermott J C, Fausti S A, Henry J A, Frey R H
Auditory Research Laboratory, US Department of Veterans Affairs Medical Center, Portland, Oreg.
Audiology. 1990;29(6):297-303. doi: 10.3109/00206099009072860.
The present study reports effects of contralateral masking on high-frequency threshold force levels in 28 normal-hearing subjects. High-frequency air- and bone-conduction thresholds were measured with a high-frequency auditory evaluation system using matched Koss HV/1A earphones and the Pracitronic KH 70/5 bone vibrator. Measurements were made for both unmasked and masked bone-conduction thresholds at the ipsilateral mastoid of the better ear. The contralateral masked condition was performed using 30-dB-SL 400-Hz narrow-band masking noise centered at frequency of test tone. The results demonstrated that masked high-frequency bone-conduction thresholds were 1.5 to 3.4 dB poorer than the unmasked thresholds and that these differences were statistically significant at 0.01 level of confidence except at 12 kHz. ANSI and ISO standards for bone-conduction threshold force levels for frequencies below 8.0 kHz have been established with contralateral masking stimuli. This study supports the need to use effective contralateral masking to eliminate cross hearing in investigations of high-frequency bone-conduction threshold measurements.
本研究报告了对28名听力正常的受试者进行对侧掩蔽时，其高频阈值力水平所受的影响。使用匹配的Koss HV/1A耳机和Pracitronic KH 70/5骨振动器，通过高频听觉评估系统测量高频气导和骨导阈值。在较好耳的同侧乳突处，分别测量了未掩蔽和掩蔽的骨导阈值。对侧掩蔽条件是使用以测试音频率为中心的30 dB-SL 400 Hz窄带掩蔽噪声。结果表明，掩蔽后的高频骨导阈值比未掩蔽的阈值差1.5至3.4 dB，并且除了在12 kHz外，这些差异在0.01的置信水平上具有统计学意义。已经通过对侧掩蔽刺激建立了8.0 kHz以下频率的骨导阈值力水平的ANSI和ISO标准。本研究支持在高频骨导阈值测量研究中需要使用有效的对侧掩蔽来消除交叉听力。
