Edwards B W, Viemeister N F
Department of Psychology, University of Minnesota, Minneapolis 55455.
J Acoust Soc Am. 1994 Apr;95(4):2202-12. doi: 10.1121/1.408680.
In an attempt to study the processing of amplitude and frequency modulation (AM and FM), detection and discrimination tasks using mixed modulation (MM) signals were performed. Modulation detection thresholds were obtained for three-component signals that span the parameter space between AM and quasi-FM. A single-cue modulation detection model predicts the thresholds with reasonable accuracy. If one assumes that the AM and FM components are extracted separately, thresholds are also well predicted if the d' of the MM signals is equal to the sum of the separate d's of the AM and FM components (two-cue summation model). This could arise from common internal noise that puts the AM and FM information along a single decision axis. A modulation discrimination task was then examined in which the subjects discriminate between signals with both different modulation depths and different modulation types. The single-cue model predicts performance well. In order for the two-cue model to predict the results, the AM and FM cues must be combined into a single statistic before a decision can be made; the listener cannot process the cues separately.
为了研究调幅和调频（AM和FM）的处理过程，使用混合调制（MM）信号进行了检测和辨别任务。针对跨越AM和准FM之间参数空间的三分量信号，获得了调制检测阈值。单线索调制检测模型能以合理的精度预测这些阈值。如果假设AM和FM分量是分别提取的，那么当MM信号的d'等于AM和FM分量各自d'之和时（双线索求和模型），阈值也能得到很好的预测。这可能源于将AM和FM信息置于单一决策轴上的共同内部噪声。接着研究了一个调制辨别任务，其中受试者要辨别具有不同调制深度和不同调制类型的信号。单线索模型能很好地预测性能。为了让双线索模型预测结果，在做出决策之前，AM和FM线索必须组合成一个单一统计量；听者无法分别处理这些线索。
