Kidd G, Mason C R, Green D M
J Acoust Soc Am. 1986 Apr;79(4):1045-53. doi: 10.1121/1.393376.
The discrimination of changes in the shapes of sound spectra is reported. The change was always an intensity increment to the 948-Hz component of a multitone complex. First, the ability of naive listeners to learn to discriminate a change in a "regular" background or reference spectrum (equal-level tones equally spaced in logarithmic frequency) was measured as a function of the number of trials. On the average, threshold improved about 10 dB over 3000 trials, with about 50% of the decrease in threshold occurring during the first 750 trials. In a subsequent series of experiments, the overall pattern of spectral shape of the background was varied randomly. Two kinds of perturbations in spectral shape were employed: Randomly choosing the frequencies of the reference spectra and randomly choosing the amplitudes of the components of the reference spectra. The experimental manipulations involved fixing the random spectra across a block of trials, varying the reference spectra from interval to interval of each trial, and providing extensive practice in discriminating specific randomly perturbed reference spectra. The results of the spectrum-learning and random perturbation experiments provide insight into the roles of critical band filtering, sensory variability, and short-term and long-term memory representations in auditory profile analysis. Further, the appropriateness of the generalization of a simple energy detection model is discussed.
本文报道了对声谱形状变化的辨别情况。这种变化总是多音复合音中948赫兹分量的强度增加。首先，测量了未经过训练的听众在“规则”背景或参考频谱（对数频率上等间隔的等电平音调）中辨别变化的能力，并将其作为试验次数的函数。平均而言，在3000次试验中，阈值提高了约10分贝，其中约50%的阈值下降发生在前750次试验中。在随后的一系列实验中，背景频谱形状的整体模式随机变化。采用了两种频谱形状的扰动：随机选择参考频谱的频率和随机选择参考频谱分量的幅度。实验操作包括在一组试验中固定随机频谱，在每次试验的不同区间改变参考频谱，并在辨别特定的随机扰动参考频谱方面提供大量练习。频谱学习和随机扰动实验的结果为临界带滤波、感觉变异性以及短期和长期记忆表征在听觉轮廓分析中的作用提供了见解。此外，还讨论了简单能量检测模型泛化的适用性。
