Gu X, Green D M
Psychology Department, University of Florida, Gainesville 32611-2065.
J Acoust Soc Am. 1994 Jul;96(1):93-101. doi: 10.1121/1.410378.
Absolute thresholds were estimated for pure tones of 500, 1000, and 2000 Hz using both a maximum-likelihood yes-no procedure and a traditional three-down one-up forced-choice adaptive procedure. Threshold estimates obtained with the two procedures were highly correlated. In the maximum-likelihood yes-no procedure, the false-alarm probability was poorly estimated. A simple change in that procedure produced less-biased estimates of the false-alarm rate. In a second experiment, the influence of the false-alarm rate on the threshold estimates was investigated. The listeners' absolute thresholds were estimated when they adopted either a liberal or conservative criterion for detecting the signals. Data were collected using both a constant-stimulus yes-no procedure and a maximum-likelihood yes-no procedure. Threshold estimates are 5 to 6 dB higher for the low than for the high false-alarm rates. Psychometric functions based on a stimulus-power model provided the best fit to the data obtained with the constant-stimulus method. This stimulus-power model was used to produce the assumed psychometric function in the maximum-likelihood yes-no procedure. Computer simulations were conducted to determine how threshold estimates were affected by the listener's inattention or by mismatches between the slope parameter of the listener's psychometric function and that assumed in the maximum-likelihood procedure.
使用最大似然是-否程序和传统的三降一升强制选择自适应程序估计了500、1000和2000赫兹纯音的绝对阈值。用这两种程序获得的阈值估计高度相关。在最大似然是-否程序中，误报概率估计不佳。对该程序进行简单更改后，对误报率的估计偏差更小。在第二个实验中，研究了误报率对阈值估计的影响。当听众采用宽松或保守的标准来检测信号时，估计了他们的绝对阈值。使用恒定刺激是-否程序和最大似然是-否程序收集数据。低误报率时的阈值估计比高误报率时高5至6分贝。基于刺激功率模型的心理测量函数最符合用恒定刺激法获得的数据。该刺激功率模型用于在最大似然是-否程序中生成假定的心理测量函数。进行了计算机模拟，以确定阈值估计如何受到听众注意力不集中或听众心理测量函数的斜率参数与最大似然程序中假定的斜率参数不匹配的影响。
