Young I M, Harbert F
Department of Otolaryngology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107.
Yonsei Med J. 1990 Sep;31(3):197-204. doi: 10.3349/ymj.1990.31.3.197.
Threshold and amplitude measurements were made for fixed frequency Bekesy pure tones on subjects with normal hearing, sensorineural hearing impairment, and functional hearing loss. Following conventional Bekesy audiometry (intensity change 4 dB/sec), -20 dB was added to a signal at the threshold of audibility (bottom of the spike). When sensation was lost at the threshold of inaudibility (top of the spike), +20 dB was added. Adding +/- 20 dB in subjects with normal hearing reduced the amplitude of the spike about 4 dB, corresponding to 1 second, for both pulsed and continuous tones. Adding +/- 40 dB produced essentially similar findings. Adding +/- 20 dB in subjects with sensorineural loss with reduced amplitude of continuous tone tracings also reduced the amplitude approximately 4 dB for pulsed tones, but 3 dB, corresponding to 0.75 seconds, for continuous tones. Abnormal rapid adaptation may account for this reduced amplitude of the spikes. A subject with multiple sclerosis producing excessive abnormal adaptation showed spectacular increased amplitude for continuous tone only when -20 dB was added at bottoms and +20 dB at tops of spikes. An explanation based on slow adaptation is offered. Subjects with functional hearing loss may emphasize either time or intensity in their inappropriate responses when +/- 20 dB is added at tops and/or bottoms of spikes.
对听力正常、感音神经性听力损失和功能性听力损失的受试者进行了固定频率的贝凯西纯音的阈值和幅度测量。在进行传统的贝凯西听力测定法（强度变化4dB/秒）后，在可听阈值（尖峰底部）的信号上加上-20dB。当在听不见的阈值（尖峰顶部）失去感觉时，加上+20dB。在听力正常的受试者中加上+/-20dB，对于脉冲音和连续音，尖峰的幅度大约降低4dB，相当于1秒。加上+/-40dB产生基本相似的结果。在连续音描记幅度降低的感音神经性听力损失受试者中加上+/-20dB，对于脉冲音，尖峰幅度也大约降低4dB，但对于连续音，降低3dB，相当于0.75秒。异常快速适应可能是尖峰幅度降低的原因。一名患有多发性硬化症且产生过度异常适应的受试者，仅在尖峰底部加上-20dB且顶部加上+20dB时，连续音的幅度才会显著增加。文中提供了基于缓慢适应的解释。当在尖峰顶部和/或底部加上+/-20dB时，功能性听力损失受试者在其不适当的反应中可能会强调时间或强度。
