The complex durational relationship of contour tones and level tones: Evidence from diachrony

The production of a contour tone requires a longer duration than the production of a level tone. This paper demonstrates that this durational relationship becomes considerably more complex when tones are realized on bimoraic sonorant units that can support both level tones and contour tones. Evidence comes from diachronic processes in which pitch and duration interact. In languages where (intrinsic) durational differences between two groups of bimoraic units lead to tonal contrasts, the longer units commonly receive a contour tone, and the shorter ones a level tone; yet over time, the units with the fully developed contour tone tend to shorten, and those with the level tone tend to lengthen. Ultimately, this can even lead to durational reversals between the units in question. The discussion focuses primarily on Franconian tone accent dialects but also incorporates data from Estonian, Hup, Las Norias Piman and North Low Saxon.