Goossens Tom, van de Par Steven, Kohlrausch Armin
Eindhoven University of Technology, Eindhoven, The Netherlands.
J Acoust Soc Am. 2009 Jun;125(6):3882-93. doi: 10.1121/1.3119626.
This study used a same/different experiment to assess the ability of human listeners to discriminate Gaussian-noise tokens with a spectral range of 350-850 Hz and a duration of 50 ms. For this duration, discrimination ability is high. However, when an identical 200-ms noise fringe with the same statistical properties as the 50-ms target tokens is appended to the end of the two target tokens, listeners show very poor discrimination. It was investigated whether altering the properties of the fringes with respect to those of the target improved the ability to discriminate the target tokens. This method was used to investigate the influence of changing fringe properties such as spectral range, level, interaural level difference, and interaural time delay on discrimination performance for the target. Spectral and temporal separation showed the strongest improvements, whereas no effect was found for doubling the fringe bandwidth, 5-dB level increases or decreases, or 10 dB interaural level differences. In the second experiment, subjects were asked to indicate whether they perceived one or two auditory objects for these stimuli. The results of the two experiments indicate that perceiving two objects is a necessary but not sufficient condition for good target discrimination.
本研究采用相同/不同实验，以评估人类听众辨别频谱范围为350 - 850赫兹、持续时间为50毫秒的高斯噪声音元的能力。在此持续时间内，辨别能力较高。然而，当在两个目标音元末尾附加一个与50毫秒目标音元具有相同统计特性的200毫秒噪声边缘时，听众的辨别能力变得非常差。研究了改变边缘相对于目标的特性是否能提高辨别目标音元的能力。该方法用于研究改变边缘特性（如频谱范围、电平、耳间电平差和耳间时间延迟）对目标辨别性能的影响。频谱和时间分离显示出最强的改善效果，而边缘带宽加倍、电平增加或减少5分贝或耳间电平差为10分贝时则未发现效果。在第二个实验中，要求受试者指出他们对于这些刺激感知到一个还是两个听觉对象。这两个实验的结果表明，感知到两个对象是良好目标辨别的必要但不充分条件。
