Multiple factors of the natural environment have been found to impact and mold the phonetic patterns of human speech, among which the potential correlation between sonority and temperature has garnered significant attention. We leverage a large database containing basic vocabularies of 5,293 languages and calculate the average sonority for each language by adopting a universal sonority scale. Our findings confirm a positive correlation between sonority and temperature across macroareas and language families, whereas this relationship cannot be discerned within language families. We suggest that the adaptation of the distribution of speech sounds within languages is a slow process which is moreover insensitive to minor differences in temperature experienced by speakers as they carry their languages to new regions. Nevertheless, at the global level a solid relationship emerges. Furthermore, we delve deeper into the nature of the relationship and contend that it is mainly due to cold temperatures having a weakening effect on sonority. This research provides compelling additional evidence that climatic factors contribute to shaping language and its evolution.
Keywords: climate; environment; evolution; language; sonority.
© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.