Laboratory of Mathematical Physics, Rockefeller University, New York, New York, USA.
PLoS One. 2013 Jun 17;8(6):e65386. doi: 10.1371/journal.pone.0065386. Print 2013.
Time-reversal symmetry breaking is a key feature of many classes of natural sounds, originating in the physics of sound production. While attention has been paid to the response of the auditory system to "natural stimuli," very few psychophysical tests have been performed. We conduct psychophysical measurements of time-frequency acuity for stylized representations of "natural"-like notes (sharp attack, long decay) and the time-reversed versions of these notes (long attack, sharp decay). Our results demonstrate significantly greater precision, arising from enhanced temporal acuity, for such sounds over their time-reversed versions, without a corresponding decrease in frequency acuity. These data inveigh against models of auditory processing that include tradeoffs between temporal and frequency acuity, at least in the range of notes tested and suggest the existence of statistical priors for notes with a sharp-attack and a long-decay. We are additionally able to calculate a minimal theoretical bound on the sophistication of the nonlinearities in auditory processing. We find that among the best studied classes of nonlinear time-frequency representations, only matching pursuit, spectral derivatives, and reassigned spectrograms are able to satisfy this criterion.
时间反转对称性破缺是许多自然声音类别中的一个关键特征，起源于声音产生的物理学。虽然已经注意到听觉系统对“自然刺激”的反应，但很少进行心理物理测试。我们对“自然”样音符（尖锐的起始，长的衰减）及其时间反转版本（长的起始，尖锐的衰减）的样式化表示进行了心理物理测量。我们的结果表明，与时间反转版本相比，这些声音具有更高的时间分辨率，从而具有更高的精度，而频率分辨率没有相应降低。这些数据反对包括时间和频率分辨率权衡在内的听觉处理模型，至少在测试的音符范围内如此，并表明具有尖锐起始和长衰减的音符存在统计先验。我们还能够计算听觉处理中非线性的最小理论界限。我们发现，在研究最多的非线性时频表示类别中，只有匹配追踪、谱导数和重分配频谱图能够满足这一标准。
