Downdrift, Downstep, and Declination

One common means of typologizing tone languages is according to their characteristics of pitch realization. In this paper I look at a set of these that has frequently been used in discussing the typology of tone languages in West Africa – the phonological and phonetic aspects of tone realization which have been grouped together as ‘downtrends’. In particular, I look at the three different downtrends mentioned in the title of this paper, downdrift, downstep, and declination. A review of the literature reveals a conflict in the use of these terms – or in identifying what has been designated by them – in that the same term has been used to refer to different phenomena, or different terms to one and the same phenomenon. This may be problematic in that it may lead to the formulation of inappropriate research questions, and thence to questionable theoretical conclusions. This paper presents instrumental data from a number of different West African languages to illustrate the nature of the problem and then offers a solution. Clarification of this issue sheds new light on the question of which aspects of pitch realization are local and which are global phenomena