The phonetics and phonology of the standard dialect of Igbo.

This thesis is a phonetic and phonological study of the Standard dialect of Igbo. The type of speech form which we refer to as the Standard dialect is defined in the first chapter of the thesis. This represents the type of speech form which is considered more 'central' with respect to the existing local dialects in the languuage, and which is more widely understood in the different localities in Igbo land. This is the dialect that has emerged as the literary dialect of Igbo; the dialect that is used in the written literature in the language, and for radio and other media broadcasts in the Igbo languaage. The thesis is organised into six chapters. The introductory first chapter states, among other things, the theoretical frarmwork for the inguistic analysis presented in the thesis. The question of dilects in the Igbo language, which has figured very prominently in the previous studies on this language, is also discussed in the first chapter. In chapter 2, the phonctic description of the speech sounds of the standard dialect is presented. Some instrumental data from mingograms, speotrograms and palatograms have been used, where necessary, in the description. The results obtained from the instrumental tests are presented in part II of the thesis. A brief analysis of the phonemic contrasts of the speech sounds is also given in chapter 2. Chapter 3 deals with the distinctive feature analysis of the phonological segments of the standard dialect. In the analysis presented in this chapter, we have used the multivalue distinctive feature system, where this is considered more appropriate than the binary distinctive feature system. The model of multivalue distinctive features we used in our analysis represents a modified version of those proposed in Ladefoged (1971/l975) in Williamson (l976). Chapter 4 deals with the morpheme structure analysis of the standard dialect, Certain generalizations describing the constraints/ redundancies in the morpheme structure of the standard dialect are stated, using the system of Morpheme structure Conditions as defined in Stanley (1967) and in Hyman (1975). chapter 5 we describe the phonological processes that operate in the Igto language. The phonological processes include vowel assimilation, vowel contraction with the resultant process of diphthongi-zation, vowel harmony etc. These phonological processes have been known to be consistent in the different dialects of Igbo. Consequently, what has been described generally for the Igbo language is, in this respect, equally relevant to the standard dialect. Chapter 6 deals with the tonology of the Igbo language. Igbo being a tone language, the question of tones plays significant role in the phonology of this language. Like the phonological processes, the features of tone are basically consistent in all the dialects of Igbo. Apart from describing the general tonological structure of Igbo, the thesis devotes special attention to the question of downstep in the language. The downstep has been at the centre of discussions in the previous studies on Igbo tonology. The downstep, no doubt, plays a stratagic role in Igbo tonology; and any views which one may hold about the downstep will obviously affect the nature of the rules that could be devised to account for the tone features and the tone changes in the language. Other problems relating to Igbo tonology are reviewed in this chapter