Ikhin Tone and Nasality: Autosegmental Effects

Abstract

In generative phonology, tone and nasality are described as suprasegmental phonological units. This implies that their survival depends on the segments on which they are grounded. Thus, when a tone bearing unit or nasality bearing unit disappears, any of these segments also disappears. In autosegmental theory, however, tone or nasality survives after the deletion of segment to which it is attached. This phenomenon is termed ‘stability’ which is the foundation for autosegmental phonological theory. Stability is the survival of tone and nasality after the deletion of segments on which they are grounded. Tone and nasality exhibit stability in Ikhin, a North-Central Edoid language spoken in Edo State, South-South, Nigeria. Previous study on Ikhin dwells mainly on the phonetics of the language. This study, therefore, investigates phonological processes such as vowel elision, glide formation and nasalization with a view to determining the stability or otherwise of tone and nasality. This paper confirms that in Ikhin, any process that involves the removal of a tone bearing unit must relate to stability and relate to the creation of contour tones. The study further confirms that nasality remains stable even in the absence of segment to which it is linked. Based on available data, it is argued that the deletion of a Tone Bearing Unit (TBU) or a Nasality Bearing Unit (NBU) does not necessarily involve the deletion of tone or nasality. Infact, it usual does not. The study concludes that tone and nasality are independent segments. They are as independent as consonant and vowel.