Humes L E
Department of Speech and Hearing Sciences, Indiana University, Bloomington 47405.
J Speech Hear Res. 1990 Mar;33(1):3-8. doi: 10.1044/jshr.3301.03.
Threshold of 4.6-ms tone bursts was measured in quiet and in the presence of a 100% sinusoidally amplitude-modulated speech-shaped noise. For the modulated-noise conditions, the onset of the tone burst coincided either with the maximum or the minimum modulator amplitude. The difference in these two masked thresholds provided an indication of the psychoacoustic modulation depth, or the modulation depth preserved within the auditory system. Modulation frequencies spanning the modulation spectrum of speech (2.5 to 20 Hz) were examined. Tone bursts were 500, 1400, and 4000 Hz. Subjects included normal listeners, normal listeners with a hearing loss simulated by high-pass noise, and hearing-impaired listeners having high-frequency sensorineural hearing loss. Normal listeners revealed a psychoacoustic modulation depth of 30-40 dB for the lowest modulation frequencies which decreased to about 15 dB at 20 Hz. The psychoacoustic modulation depth was decreased in the normal listeners with simulated hearing loss and in the hearing-impaired listeners. There was general agreement in the data, however, for the latter two groups of listeners suggesting that the normal listeners with hearing loss simulated by an additional masking noise provided a good representation of the performance of hearing-impaired listeners on this task.
在安静环境以及存在100%正弦幅度调制的言语形状噪声的情况下，测量了4.6毫秒纯音猝发的阈值。对于调制噪声条件，纯音猝发的起始与调制器幅度的最大值或最小值一致。这两个掩蔽阈值的差异提供了心理声学调制深度的指标，即听觉系统内保留的调制深度。研究了涵盖言语调制频谱（2.5至20赫兹）的调制频率。纯音猝发频率为500、1400和4000赫兹。受试者包括正常听力者、通过高通噪声模拟听力损失的正常听力者以及患有高频感音神经性听力损失的听力受损者。正常听力者在最低调制频率下的心理声学调制深度为30 - 40分贝，在20赫兹时降至约15分贝。在模拟听力损失的正常听力者和听力受损者中，心理声学调制深度降低。然而，后两组受试者的数据总体一致，这表明通过额外掩蔽噪声模拟听力损失的正常听力者能很好地代表听力受损者在此任务上的表现。
