Grassi Massimo, Mioni Giovanna
Department of General Psychology, University of Padova, Via Venezia 8, 35131, Padova, Italy.
Atten Percept Psychophys. 2020 Aug;82(6):2775-2784. doi: 10.3758/s13414-020-02059-2.
Hearing is the most accurate sense for perceiving duration. However, rarely it produces inaccurate estimates of duration, for example when it compares the subjective duration of tones that are increasing in intensity over time (i.e., ramped) with that of tones that are decreasing in intensity over time (i.e., damped). The literature reports that the damped tones are perceived as much being shorter than the ramped tones of the same length. The short subjective duration of damped tones may originate from a decay suppression mechanism that parses the source-informative part of many natural sounds (i.e., the beginning) from the less informative part of them (the decay): listeners may interpret the tail of damped tones like an echo or like the decay portion of an impact sound and exclude it from the account of the duration of the tone. In the natural soundscape, the tail of sounds produced in reverberant environments and the tail of impact sounds have a frequency content that is constant throughout the sound's duration. Here, the carriers used for ramped and damped sounds were a tone constant in frequency and a tone modulated in frequency. The frequency modulation was introduced to prevent the listener from interpreting the tail of these tones as the result of reverberation or the decay portion of an impact sound. Frequency constant damped tones were largely underestimated in duration whereas frequency modulated ones were not (or were only slightly), demonstrating that the decay suppression mechanism is a worthy explanation for the short subjective duration of damped tones.
听觉是感知时长最精确的感官。然而，它很少会产生对时长的不准确估计，例如，当它将强度随时间增加（即渐变）的音调的主观时长与强度随时间减少（即衰减）的音调的主观时长进行比较时。文献报道，衰减音调被感知为比相同长度的渐变音调短得多。衰减音调较短的主观时长可能源于一种衰减抑制机制，该机制将许多自然声音的源信息部分（即开头）与信息较少的部分（衰减）区分开来：听众可能会将衰减音调的尾部解释为回声或撞击声的衰减部分，并将其排除在音调时长的计算之外。在自然声景中，混响环境中产生的声音的尾部和撞击声的尾部在整个声音持续时间内的频率成分是恒定的。在这里，用于渐变和衰减声音的载波是频率恒定的音调和频率调制的音调。引入频率调制是为了防止听众将这些音调的尾部解释为混响的结果或撞击声的衰减部分。频率恒定的衰减音调在时长上大多被低估，而频率调制的衰减音调则没有（或只是略有低估），这表明衰减抑制机制是对衰减音调较短主观时长的一个合理的解释。
