This study analyzes the effect of consonant context and speaking rate on vowel space and coarticulation in Toda vowel-consonant-vowel (VCV) sequences. Five vowels, /a/, /e/, /i/, /o/, /u/, and two intervocalic consonants, /p/ (labial) and /t/ (alveolar), are considered to form asymmetrical VCV sequences in slow and very fast speaking rates. Acoustic analysis using first and second formants (F1 and F2) shows a significant change in vowel space across speaking rates in a consonant specific manner. Quantification of range and extent of coarticulation using F2 are presented to carry out acoustic analysis of both anticipatory and carryover coarticulation. Significant effect of consonant context is found for both anticipatory and carryover coarticulation in most of the VCV sequences. Increase in speaking rate is found to significantly drop both anticipatory and carryover coarticulation range in the context of alveolar consonants. Results from these acoustic analyses indicate that there are differences in the nature in which rate and consonant context affect the coarticulatory organization.

本研究分析了辅音上下文和语速对 Toda 元音-辅音-元音 (VCV) 序列中元音空间和连音的影响。五个元音 /a/、/e/、/i/、/o/、/u/ 和两个声间辅音 /p/（唇）和 /t/（牙槽）被认为形成了不对称的 VCV 序列语速缓慢和非常快。使用第一和第二共振峰（F1 和 F2）的声学分析显示，元音空间以辅音特定方式在语速上发生显着变化。提出了使用 F2 对 coarticulation 的范围和程度进行量化，以对预期和结转 coarticulation 进行声学分析。在大多数 VCV 序列中，辅音上下文对预期和结转联发音都有显着影响。在牙槽辅音的背景下，语速的增加被发现显着降低了预期和遗留的共同发音范围。这些声学分析的结果表明，速率和辅音上下文影响发音组织的性质存在差异。