Dissard P, Darwin C J
University of Sussex, Brighton, United Kingdom.
J Acoust Soc Am. 2000 Feb;107(2):960-9. doi: 10.1121/1.428277.
The four experiments reported here measure listeners' accuracy and consistency in adjusting a formant frequency of one- or two-formant complex sounds to match the timbre of a target sound. By presenting the target and the adjustable sound on different fundamental frequencies, listeners are prevented from performing the task by comparing the absolute or relative levels of resolved spectral components. Experiment 1 uses two-formant vowellike sounds. When the two sounds have the same F0, the variability of matches (within-subject standard deviation) for either the first or the second formant is around 1%-3%, which is comparable to existing data on formant frequency discrimination thresholds. With a difference in F0, variability increases to around 8% for first-formant matches, but to only about 4% for second-formant matches. Experiment 2 uses sounds with a single formant at 1100 or 1200 Hz with both sounds on either low or high fundamental frequencies. The increase in variability produced by a difference in F0 is greater for high F0's (where the harmonics close to the formant peak are resolved) than it is for low F0's (where they are unresolved). Listeners also showed systematic errors in their mean matches to sounds with different high F0's. The direction of the systematic errors was towards the most intense harmonic. Experiments 3 and 4 showed that introduction of a vibratolike frequency modulation (FM) on F0 reduces the variability of matches, but does not reduce the systematic error. The experiments demonstrate, for the specific frequencies and FM used, that there is a perceptual cost to interpolating a spectral envelope across resolved harmonics.
这里报告的四项实验测量了听众在调整一或双共振峰复合声音的共振峰频率以匹配目标声音音色时的准确性和一致性。通过在不同基频上呈现目标声音和可调节声音，听众无法通过比较分辨出的频谱成分的绝对或相对水平来完成任务。实验1使用双共振峰类元音声音。当两种声音具有相同的基频时，第一或第二共振峰匹配的变异性（受试者内标准差）约为1%-3%，这与现有的共振峰频率辨别阈值数据相当。当基频存在差异时，第一共振峰匹配的变异性增加到约8%，但第二共振峰匹配的变异性仅增加到约4%。实验2使用在1100或1200赫兹处有单个共振峰的声音，两种声音的基频均为低或高。对于高基频（其中靠近共振峰峰值的谐波是可分辨的），由基频差异产生的变异性增加比低基频（其中谐波不可分辨）时更大。听众在与不同高基频声音的平均匹配中也表现出系统误差。系统误差的方向指向最强的谐波。实验3和4表明，在基频上引入类似颤音的频率调制（FM）可降低匹配的变异性，但不会降低系统误差。这些实验表明，对于所使用的特定频率和FM，在分辨出的谐波上内插频谱包络存在感知代价。
