The Description of Terraced-Level Tone Languages

While tone terracing appears superficially to be a purely phonetic phenomenon, it is frequently subject to syntactic, grammatical, and lexical conditions which are not phonetically definable in surface structure; and this raises the question of how such conditions are to be encoded at the phonetic level to which pitch assignment rules apply. Some studies (e.g. Johnson 1972, Peters 1973, Anderson 1978) have proposed treating downstepped tones as separate ‘tonemes’ (distinguished from other tones in their feature characterization) to which pitch assignment rules apply in a left-to-right iterative mode of application. Such proposals fail to provide an explanation for the phonetic equivalence of basic and derived downstepped tones, and for the equivalence of downstepped and the corresponding non-downstepped tones with respect to following tones. In the alternative treatment proposed here, tone terracing systems are described in terms of a model which provides an independent level of representation to which intonational processes, including register lowering (downstep) apply; such a model is applied to the description of the tone terracing system of Akan. Further evidence for this model is drawn from Kikuyu.