Miśkiewicz A, Scharf B, Hellman R, Meiselman C
Auditory Perception Laboratory, Northeastern University, Boston, Massachusetts 02115.
J Acoust Soc Am. 1993 Sep;94(3 Pt 1):1281-6. doi: 10.1121/1.408154.
Loudness adaptation was measured for pure tones at 4, 12, 14, and 16 kHz. In three experiments, a total of 87 young listeners judged--by the method of successive magnitude estimation--the loudness of the tones over a 6-min exposure period. Thresholds were measured by an adaptive 2IFC procedure. Although earlier measurements had shown that adaptation near threshold increases with frequency, these new data reveal that the increase is especially marked at higher sensation levels. Thus, at 40 dB SL, over a 6-min period loudness declined by 18% at 4 kHz and by 94% at 16 kHz. Moreover, the 4-kHz tone remained audible for all listeners throughout the 6-min exposure period whereas the 16-kHz tone became inaudible for two-thirds of them by the end of the exposure period. Listeners with relatively low thresholds (< 50 dB SPL) at 16 kHz showed much less adaptation at 14 kHz than at 16 kHz and much less than listeners with relatively high thresholds (> 50 dB SPL) at 16 kHz; this latter group showed strong adaptation at 14 kHz. The marked loudness adaptation of steady tones at very high frequencies and relatively high sensation levels is associated with a restricted spread of excitation in the auditory system resulting from the steep rise of the threshold curve at the highest audible frequencies.
针对4千赫、12千赫、14千赫和16千赫的纯音测量了响度适应性。在三个实验中，共有87名年轻听众通过连续量级估计法判断了在6分钟暴露期内这些纯音的响度。阈值通过自适应二间隔强迫选择程序进行测量。尽管早期测量表明，阈值附近的适应性随频率增加，但这些新数据显示，在较高的感觉水平下，这种增加尤为明显。因此，在40分贝感觉级时，在6分钟内，4千赫的响度下降了18%，16千赫的响度下降了94%。此外，在整个6分钟暴露期内，所有听众都能听到4千赫的纯音，而到暴露期结束时，三分之二的听众听不到16千赫的纯音。在16千赫处阈值相对较低（<50分贝声压级）的听众在14千赫处的适应性比在16千赫处小得多，且比在16千赫处阈值相对较高（>50分贝声压级）的听众小得多；后一组听众在14千赫处表现出强烈的适应性。在非常高的频率和相对较高的感觉水平下，稳定纯音的明显响度适应性与听觉系统中兴奋传播受限有关，这是由于在最高可听频率处阈值曲线急剧上升所致。
