Monophthongisation and Vowel Lengthening Processes in Educated Urhobo English: A Moraic Account

Abstract

This paper studies monophthongisation and vowel lengthening processes in Educated Urhobo English (hereafter, EUE). EUE is an ethnic variety of Nigerian English spoken by literate home-grown Urhobo people in Delta State, Nigeria.  Monophthongisation  is a phonological process whereby one of two vowel elements of a diphthong, usually the second (offset) element, is deleted, leaving the stranded (onset) one lengthened, if found in final open, stressed syllable.  Existing works on EUE segmentals have pointed to the fact that two of four Standard British English (SBE) closing diphthongs, /e?/ and /??/, also known as homogenous diphthongs, tend to monophthongise to [e] and [o] respectively. However, the works have often ignored the aspect of length which accompanies these simplified units whenever they occurred in final open syllable. As one of the striking phonological features which characterise EUE phonology, this paper undertook the study of [e]- and [o]-lengthening to [e: and [o:] respectively, with a view to explaining the motivation for the lengthening. Using the paradigms of moraic theory, the study established the fact that the monophthongised diphthongs were lengthened for two main reasons: (1) by the need to preserve the weight of the deleted /?/ and /?/, in SBE /e?/ and /??/ diphthongs, and (2) in order to reflect components of the falling Fundamental Frequency (F0) contour of English final open syllables. Speech Filling System (SFS/WASP) computerised speech laboratory was used to interprete F0 curve structure and acoustic duration in order to corroborate findings from perceptual analysis.  However, it is  suggests that these two factors appear to underlie the simplification of the same set of closing diphthongs in many non-native English accents of Africa and Asia such as Southern Nigerian English, Zimbabwean (Shona) English, India English, among many others.

Keywords: Educated Urhobo English, Monopthongisation, Vowel lengthening, Closing diphthongs, Moraic theory