MRC Cognition and Brain Sciences Unit, Cambridge Hearing Group, University of Cambridge, 15 Chaucer Road, Cambridge, CB2 7EF, UK.
Sci Rep. 2023 Aug 15;13(1):13247. doi: 10.1038/s41598-023-40122-8.
Difference limens for fundamental frequency (F0), F0DLs, are usually small for complex tones containing low harmonics that are resolved in the auditory periphery, but worsen when the rank of the lowest harmonic increases above about 6-8 and harmonics become less resolved. The traditional explanation for this, in terms of resolvability, has been challenged and an alternative explanation in terms of harmonic rank was suggested. Here, to disentangle the effects of resolvability and harmonic rank the complex tones were presented either diotically (all harmonics to both ears) or dichotically (even and odd harmonics to opposite ears); the latter increases resolvability but does not affect harmonic rank. F0DLs were measured for 14 listeners for complex tones containing harmonics 6-10 with F0s of 280 and 1400 Hz, presented diotically or dichotically. For the low F0, F0DLs were significantly lower for the dichotic than for the diotic condition. This is consistent with a benefit of increased resolvability of harmonics for F0 discrimination and extends previous results to harmonics as low as the sixth. In contrast, for the high F0, F0DLs were similar for the two presentation modes, adding to evidence for differences in pitch perception between tones with low-to-medium and very-high frequency content.
基频（F0）和 F0DL 的差异阈限通常很小，适用于在听觉外围得到解析的包含低频谐波的复音，但当最低谐波的阶数增加到 6-8 以上且谐波变得不那么可解析时，情况会恶化。传统上，从可解析性的角度对这种情况进行了解释，但这一解释受到了挑战，人们提出了一种基于谐波阶数的替代解释。在这里，为了理清可解析性和谐波阶数的影响，分别用立体声（所有谐波都传入双耳）或立体声（偶数和奇数谐波传入对侧耳）呈现包含 6-10 个谐波的复音；后者增加了可解析性，但不影响谐波阶数。14 位听众分别用立体声和立体声呈现 F0 为 280 和 1400Hz 的复音，测量了这些复音的 F0DL。对于低频 F0，立体声条件下的 F0DL 明显低于立体声条件。这与增加谐波的可解析性有助于 F0 辨别一致，并且将之前的结果扩展到了低至第六谐波的情况。相比之下，对于高频 F0，两种呈现模式下的 F0DL 相似，这增加了在具有低频至中频和极高频率内容的音之间的音高感知差异的证据。
