The Sound Systems of Languages Adapt, But to What Extent?

Abstract

The sound systems of the world’s languages adapt to biomechanical, aerodynamic and cognitive pressures associated with sound production and discrimination. Such pressures help to yield the greater frequency of some sound types and the reduced frequency of others. In this paper I explore such adaptation, pointing out that sound systems not only adapt to such pressures in ways that are clear from a typological perspective, but that they adapt in more subtle ways that are only now becoming apparent. Furthermore, I survey a host of recent studies suggesting that sound systems likely adapt to some pressures that vary across populations and environments. While the extent of adaptation to such variable pressures is certainly debatable, the mere existence of phonetic/phonological adaptation to pressures that differ across populations is increasingly well supported. The evidence in support of such adaptation ranges from large-scale quantitative data, to biomechanical modeling, to the speech of Freddie Mercury.

Challenges of sampling and how phylogenetic comparative methods help: With a case study of the Pama-Nyungan laminal contrast

“…In the first scenario, material is passed directly between taxa, such as lateral transfer of genetic material between species, especially but not exclusively in prokaryotic life forms such as bacteria (Keeling & Palmer 2008), or borrowing between languages. In the second scenario there is no direct transfer of material, rather a shared environment leads to similar developments in taxa, such as parallel dwarfism on islands or, in some cases more contentiously, parallel conditioning of language by its environment (Everett, Blasi & Roberts 2015, Everett 2017, Blasi, Michaelis & Haspelmath 2017, Everett 2021. In both kinds of scenario, there is a causal, areally-correlated contribution to similarity which is separate from the contribution due to shared genealogy.…”

Investigating environmental effects on phonology using diachronic models

“…Caleb Everett extended this line of research using evidence from anatomical responses of the speech organs to the climate in order to bridge the theoretical gap around production effort (Everett, 2013(Everett, , 2021. He argued for the following causal chain: ambient humidity → vocal fold desiccation → voicing control → linguistic dependence on voicing.…”

“…Secondly, we use methods from causal inference to design a novel regression analysis that can control for various confounding effects such as inheritance, borrowing and geographic proximity. We focus on claims that, over thousands of years, properties of the environment can affect the sound structures of a spoken language (Everett, 2021 ), specifically the effect of humidity on lexical tone (Everett, Blasi, & Roberts, 2015 ) and vowel inventories (Everett, 2017 ). Our aim is to contribute to the methodology for testing whether these claims are robust or based on spurious correlations.…”