Phonetically incomplete neutralisation can be phonologically complete: evidence from Huai’an Mandarin

The phenomenon of incomplete neutralisation describes a situation where a putative case of categorical phonological neutralisation is observed to be phonetically non-neutralising. This has been argued to be a problem for phonological theories that employ categorical features. Here, we use two distinct feeding orders of tone sandhi processes from Huai’an Mandarin to show that incomplete phonetic neutralisation is compatible with categorical phonological phenomena. Therefore, incomplete phonetic neutralisation does not automatically inform us of gradient phonological representations. We further show that incomplete phonetic neutralisation can in fact have a large effect size. Such results are not surprising from a classic generative view of phonology where linguistic performance is argued to be a multi-factorial problem, and linguistic knowledge (i.e., competence) is only one of the many factors involved. Furthermore, our results suggest that the observed incompleteness or gradience may have a source outside phonological knowledge.