An acoustic comparison between two pairs of assimilatory and dissimilatory tone sandhi processes in Nanjing Mandarin in categoricalness/ gradience

The current study aims to investigate the categoricalness versus gradience of tone sandhi application in assimilatory and dissimilatory tone sandhi processes, within the setting of one language. Our hypotheses were that (a) assimilatory processes can be gradient, based on their articulatory motivation; and (b) dissimilatory processes should always be categorical, hence never show any gradient application, based on Ohala's “hypercorrection” theory. We selected in Nanjing Mandarin two pairs of comparable assimilatory and dissimilatory tone sandhi processes based on previous researchers' observations. Results show a near-categorical assimilatory Sandhi 1 and a gradient assimilatory Sandhi 3, congruent with the prediction that assimilatory processes are allowed to apply in a gradient fashion. Though we found that dissimilatory Sandhi 4 is a categorical process, our observation of gradience in dissimilatory Sandhi 2 suggests that dissimilatory changes can also occur in a gradient way, which contradicts the prediction by the “hyper-correction” account.