A REVIEW OF VOWEL ELISION AND ASSIMILATION IN IGBO: CLARIFICATION THROUGH ACOUSTIC, PERCEPTUAL AND THEORETICAL ANALYSIS.

There seems to be confusion in the data presented by some authors (see Onuora, 2012; Emenanjo, 1991; Ngoesi, 2000; Omozuwa, 2021) in explaining elision and assimilation in Igbo; as similar items are presented as assimilation on one hand, and as elision on the other hand. While Onuora (2012); Emenanjo (1991); and Ngoesi (2000) claim that the vowels are first completely assimilated before they are elided, Omozuwa (2021) does not see any assimilation in them; for him, they are all cases of elision. This aroused the researchers' curiosity, leading to the investigation of vowel elision and assimilation in Igbo through oral data and data from these authors. The study uses perceptual, acoustic and theoretical analysis to study the duration of the vowels in order to clarify the contentious issue. The findings reveal that apart from a few instances of diachronic elision, all the vowels analysed as elided in the studies are only assimilated; not elided. They are instances of complete vowel assimilation where the phonetic features of one vowel are completely assimilated by another vowel, making the vowels to be identical. Such identical vowels align with theoretical analysis as instances of assimilation, they are perceptually longer in length than their single counterparts, and they clearly show that their duration, whether they bear same or different tones, is approximately double the duration of a single vowel of same acoustic features. Also, the study does not confirm earlier claims that elision and assimilation in Igbo occur only in fast, casual speech; instead, it shows them to also occur in normal free flow speech. [ABSTRACT FROM AUTHOR]