Goossens Tom, van de Par Steven, Kohlrausch Armin
Eindhoven University of Technology, P.O. Box 513, NL-5600 MB Eindhoven, The Netherlands.
J Acoust Soc Am. 2008 Oct;124(4):2251-62. doi: 10.1121/1.2973184.
This study investigated factors that influence a listeners' ability to discriminate Gaussian-noise stimuli in a same-different discrimination paradigm. The first experiment showed that discrimination ability increased with bandwidth for noise durations up to 100 ms. Duration had a nonmonotonic influence on performance, with a decrease in discriminability for stimuli longer than 40 ms. Further experiments investigated the cause for this performance decrease. They showed that discriminability could be improved when using frozen-noise tokens and by instructing listeners to focus on the stimulus endings. A final experiment, using a stimulus consisting of 5 ms Hanning-windowed tone-bursts randomly distributed over time, investigated whether stimulus duration and amount of information differently affect the processing capacity of the auditory system. Results showed that the number of degrees of freedom in the stimulus, not its duration, predominantly influenced the ability to discriminate. Overall, the results suggest that the discrimination performance for acoustic stimuli depends strongly on the amount of information per critical band and the capacity to process this information. This capacity seems to be limited in the temporal dimension, while extending the signal over more auditory filters does have a positive effect on performance.
本研究调查了在异同辨别范式中影响听众辨别高斯噪声刺激能力的因素。第一个实验表明，对于持续时间长达100毫秒的噪声，辨别能力随带宽增加而提高。持续时间对表现有非单调影响，对于持续时间超过40毫秒的刺激，辨别能力会下降。进一步的实验研究了这种表现下降的原因。结果表明，使用冻结噪声样本并指导听众关注刺激结尾时，辨别能力可以得到提高。最后一个实验使用了由5毫秒汉宁窗调幅脉冲组成的刺激，这些脉冲随时间随机分布，研究了刺激持续时间和信息量是否会对听觉系统的处理能力产生不同影响。结果表明，刺激中的自由度数量而非其持续时间，对辨别能力起主要影响作用。总体而言，结果表明声学刺激的辨别表现强烈依赖于每个临界带宽的信息量以及处理该信息的能力。这种能力在时间维度上似乎是有限的，而将信号扩展到更多听觉滤波器上确实对表现有积极影响。
