Demany L, Semal C
Laboratoire de Psychoacoustique, Université de Bordeaux II, France.
J Acoust Soc Am. 1989 Mar;85(3):1295-301. doi: 10.1121/1.397460.
An adaptive forced-choice procedure was used to measure, in four normal-hearing subjects, detection thresholds for sinusoidal frequency modulation as a function of carrier frequency (fc, from 250 to 4000 Hz) and modulation frequency (fmod. from 1 to 64 Hz). The results show that, for a wide range of fmod values, fc and fmod have almost independent effects on the thresholds when the thresholds are expressed as just-noticeable frequency swings and plotted on a log scale. In two subjects, the effect of fc on the thresholds was compared to the effect of standard frequency on the frequency just noticeable differences (jnd's) of successive and steady tones. In agreement with previous data [H. Fastl, J. Acoust. Soc. Am. 63, 275-277 (1978)], it was found that the two effects are significantly different if the frequency jnd's are measured with long-duration tones. However, it was also found that the two effects are similar if the frequency jnd's are measured with 25-ms tones. These results support the idea that, at least for low fmod values, the detection of continuous and periodic frequency modulations is mediated by a pitch-sampling process using a temporal window of about 25 ms.
采用自适应强制选择程序，对4名听力正常的受试者测量了正弦频率调制的检测阈值，该阈值是载波频率（fc，范围为250至4000Hz）和调制频率（fmod，范围为1至64Hz）的函数。结果表明，在很宽的fmod值范围内，当阈值以刚好可察觉的频率摆动表示并绘制在对数尺度上时，fc和fmod对阈值的影响几乎相互独立。在两名受试者中，将fc对阈值的影响与标准频率对连续和稳定音调的频率刚好可察觉差异（jnd）的影响进行了比较。与先前的数据[H. Fastl，J. Acoust. Soc. Am. 63, 275 - 277 (1978)]一致，发现如果用长时音调测量频率jnd，则这两种影响有显著差异。然而，还发现如果用25毫秒的音调测量频率jnd，则这两种影响相似。这些结果支持这样一种观点，即至少对于低fmod值，连续和周期性频率调制的检测是由使用约25毫秒时间窗口的音调采样过程介导的。
