Carlyon R P
Laboratory of Experimental Psychology, Sussex University, England.
J Acoust Soc Am. 1991 Jan;89(1):329-40. doi: 10.1121/1.400468.
A series of experiments measured the discrimination by human listeners of frequency-modulated complex tones which differed only in the coherence of frequency modulation (FM). For the coherently modulated tones all components were modulated by the same 5-Hz sinusoid, and by the same percentage of their starting frequencies, whereas for the incoherently modulated tones the modulation of one (target) component differed from that of the rest. When the 400-ms complex was composed of consecutive harmonics of a common fundamental, performance improved monotonically with increases in modulator delay, and was nearly perfect at the longest delays. When the complex was inharmonic, performance was near chance at all modular delays, both for component frequencies between 1500 and 2500 Hz, and for component frequencies between 400 and 800 Hz. It is argued that listeners detected incoherence in harmonic complexes by detecting the resulting mistuning of the target component. This conclusion was supported by the finding that listeners were usually at least as good at detecting a fixed mistuning of the center component of a harmonic complex as they were at detecting a modulator phase delay imposed on it. A final experiment, with a stimulus duration of 1 s and slower modulation rates, showed that listeners could detect incoherence for some inharmonic complexes. However, detection was worse than for harmonic complexes and was, it is argued, based on weak harmonicity cues. The results of all experiments point to the absence of an across-frequency mechanism specific to the detection of FM incoherence.
一系列实验测量了人类听众对仅在调频（FM）连贯性上存在差异的调频复合音的辨别能力。对于连贯调制的音调，所有成分都由相同的5赫兹正弦波调制，且调制频率占其起始频率的百分比相同；而对于非连贯调制的音调，一个（目标）成分的调制与其他成分不同。当400毫秒的复合音由一个共同基频的连续谐波组成时，随着调制器延迟的增加，辨别性能单调提高，在最长延迟时几乎达到完美。当复合音为非谐波时，对于1500至2500赫兹之间的成分频率以及400至800赫兹之间的成分频率，在所有调制延迟下的辨别性能都接近随机水平。有人认为，听众通过检测目标成分产生的失谐来检测谐波复合音中的不连贯性。这一结论得到了以下发现的支持：听众通常至少同样擅长检测谐波复合音中心成分的固定失谐，就像他们擅长检测施加在其上的调制器相位延迟一样。最后一个实验，刺激持续时间为1秒且调制速率较慢，结果表明听众能够检测到一些非谐波复合音中的不连贯性。然而，检测效果比谐波复合音差，并且据认为是基于微弱的谐波线索。所有实验结果都表明不存在专门用于检测调频不连贯性的跨频率机制。
