Commentary: Tonal complexity in non-tonal languages

Everett et al. (2015) established that complex tone languages are frequent in humid and warm areas and sparse in colder and dryer ones, proposing that this finding is to be explained by a less efficient vibration process of the vocal folds in dryer climates. Everett et al. (2016) are making the case that this result merits research addressing the hypothesis that the deleterious effects of laryngeal desiccation on voicing affects the phonological structures of languages. Their additional plea is that such efforts might preferably be methodologically varied and address predictions that are formulated from different perspectives along the presumed chain of cause and effect. My response addresses the question whether the prediction can be tested on a different typological group of languages, their class of pitch accent languages and non-tonal languages. Two issues here are the extent to which variation in complexity can be established in this group of languages and, assuming the answer is affirmative, the definition of an appropriate complexity measure for them. Everett et al. (2016) observe that the lexical functional load in tone languages is higher than in languages ‘in which this burden typically affects at most one syllable per word’ or languages where ‘pitch modulation is mostly used to convey pragmatic information at the phrasal level’. Before considering the relevance of these languages to the research issue, I would like to make some typological comments. The characterization of one syllabic tone contrast per word arguably covers all the indigenous European language varieties which have been described as having lexical tone, like varieties of Northern Bizkaian Basque, Norwegian–Swedish, Latvian, Lithuanian, Limburgish–Central Franconian, Bosnian–Croatian–Serbian–Slovenian (van der Hulst 1999). It is in fact hard to see such languages as a coherent group. Even just the European group represents a typologically quite varied collection. Judging by the Lekeitio variety …