Kortekaas Reinier, Buus Søren, Florentine Mary
Institute of Hearing, Speech & Language, Department of Speech-Language Pathology & Audiology (106A FR), Northeastern University, Boston, Massachusetts 02115, USA.
J Acoust Soc Am. 2003 Jun;113(6):3306-22. doi: 10.1121/1.1570441.
Perceptual weights in level discrimination (also called intensity discrimination) were determined for 3-, 7-, 15-, and 24-component tone complexes with flat spectral envelopes using a correlational paradigm. Each frequency component was randomly and independently perturbed in level oneach presentation. For the target interval, frequency-component levels were additionally increased by the level increment to be detected, deltaL [= 201og10((p + deltap)/p), where p is pressure]. Weights were calculated from the across-trial correlation between the level perturbations for each frequency component and the interval chosen by the listener. Two conditions were investigated: (1) deltaL was equal across frequency components, and (2) deltaL increased progressively across frequency components. For both conditions, data for four listeners usually showed the greatest weight for the highest frequency component. The two-to-four highest frequency components generally were most important for level discrimination. The effect of increasing deltaL progressively with frequency was small and inconsistent. Additional measurements showed that flanking noise maskers designed to mask spread of excitation caused only small and generally unsystematic changes to the weights. Overall, these results indicate that listeners combine information across a wide range of auditory channels to arrive at a decision for level discrimination, but the weighting of channels appears to be suboptimal.
使用相关范式，针对具有平坦频谱包络的3、7、15和24分量音调复合体，确定了响度辨别（也称为强度辨别）中的感知权重。每次呈现时，每个频率分量的响度都会随机且独立地受到干扰。对于目标间隔，频率分量的响度会额外增加要检测的响度增量，即deltaL [= 20log10((p + deltap)/p)，其中p为声压]。权重是根据每个频率分量的响度干扰与听众选择的间隔之间的跨试验相关性计算得出的。研究了两种情况：（1）各频率分量的deltaL相等；（2）deltaL随频率逐渐增加。在这两种情况下，四位听众的数据通常显示最高频率分量的权重最大。频率最高的两到四个分量通常对响度辨别最为重要。deltaL随频率逐渐增加的影响较小且不一致。额外的测量表明，旨在掩盖兴奋扩散的侧翼噪声掩蔽器只会对权重产生微小且通常无系统规律的变化。总体而言，这些结果表明，听众会综合来自广泛听觉通道的信息来做出响度辨别决策，但通道的加权似乎并不理想。
