PERCEPTUAL SEPARATION OF SIMULTANEOUS VOWELS - WITHIN AND ACROSS-FORMANT GROUPING BY FO
PERCEPTUAL SEPARATION OF SIMULTANEOUS VOWELS - WITHIN AND ACROSS-FORMANT GROUPING BY FO
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DOI：
10.1121/1.405675
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发表时间：
1993-06-01
影响因子：
2.4
通讯作者：
DARWIN, CJ
中科院分区：
文献类型：
--
作者：
CULLING, JF;DARWIN, CJ
六个实验探讨了为什么对一对异质、同步、稳态元音的两个成员的识别随着基频（DELTAF0）的不同而提高。实验1证实了先前的报道，即DELTAF0提高了对持续时间为200毫秒而不是50毫秒的“双元音”的识别；识别提高到1半音DELTAF0，然后渐近线。在这种刺激下，一个给定元音的所有共振峰都被同一个F0激发，为听者提供了潜在的分组提示。随后的实验询问，对较长元音的DELTAF0识别的提高是否由于听者在一对元音的每个元音中使用一致的F0来适当地分组共振峰。单个元音在第一个形成峰区域与在较高的形成峰区域用不同的F0合成。这样的元音然后配对，使一个元音的第一个共振峰与另一个元音的较高共振峰具有相同的F0。这些F0的跨构象不一致并没有实质性地降低先前增加最多4个半音的DELTAF0的识别率的提高（实验2）。在不一致条件下，随着DELTAF0的增加，受试者的改善不是仅仅基于第一峰区或高峰区信息来识别元音，因为单独包含这两个区域中的任何一个的刺激都很难被受试者识别。此外，对于较大的DELTAF0，不一致条件确实会导致较差的识别（实验3）。当元音对之间的DELTAF0被限制在第一共振峰区域时（实验4），对不一致刺激的DELTAF0识别的改善仍然存在，但当它被限制在更高的共振峰区域时（实验6）则没有改善。在不同的整体呈现水平下，结果是重复的（实验5）。实验表明，在较小的DELTAF0下，只有第一峰区域有助于提高识别精度，而在较大的DELTAF0下，较高的峰区域也可能有助于提高识别精度。这种差异可能与其他结果有关，这些结果表明，在编码音高中，分辨谐波比未分辨谐波更优越。
Six experiments explored why the identification of the two members of a pair of diotic, simultaneous, steady-state vowels improves with a difference in fundamental frequency (DELTAF0). Experiment 1 confirmed earlier reports that a DELTAF0 improves identification of 200-ms but not 50-ms duration ''double vowels''; identification improves up to 1 semitone DELTAF0 and then asymptotes. In such stimuli, all the formants of a given vowel are excited by the same F0, providing listeners with a potential grouping cue. Subsequent experiments asked whether the improvement in identification with DELTAF0 for the longer vowels was due to listeners using the consistent F0 within each vowel of a pair to group formants appropriately. Individual vowels were synthesized with a different F0 in the region of the first formant peak from in the region of the higher formant peaks. Such vowels were then paired so that the first formant of one vowel bore the same F0 as the higher formants of the other vowel. These across-formant inconsistencies in F0 did not substantially reduce the previous improvement in identification rates with increasing DELTAF0's of up to 4 semitones (experiment 2). The subjects' improvement with increasing DELTAF0 in the inconsistent condition was not produced by identifying vowels on the basis of information in the first-formant or higher-formant regions alone, since stimuli which contained either of these regions in isolation were difficult for subjects to identify. In addition, the inconsistent condition did produce poorer identification for larger DELTAF0's (experiment 3). The improvement in identification with DELTAF0 found for the inconsistent stimuli persisted when the DELTAF0 between vowel pairs was confined to the first formant region (experiment 4) but not when it was confined to the higher formants (experiment 6). The results replicate at different overall presentation levels (experiment 5). The experiments show that at small DELTAF0's only the first-formant region contributes to improvements in identification accuracy, whereas with larger DELTAF0's the higher formant region may also contribute. This difference may be related to other results that demonstrate the superiority of resolved rather than unresolved harmonics in coding pitch.