The author investigates whether geographic factors--namely high elevation or 1500 m+ above sea level (reduced atmospheric pressure)-- impact the production, use, and ubiquity of ejective phonemes in eight non-contiguous language clusters. It is suggested that increased use of ejective phonemes has a physiological benefit: the reduction of water vapor loss via exhaled air. Evidence is presented in support of the hypothesized geographic-phonetic linkage.

In the field of bioacoustics, the Acoustic Adaptation theory suggests that variation in vocalization across different species can be accounted for by the acoustic properties of different habitats. Here, the researchers test consonant- and vowel-heaviness in human languages against various environmental variables in order to examine the theory's potential application to our own species. The authors identify a significant negative correlation between consonant heaviness and temperature, precipitation, and tree cover, and some positive correlation with rugosity and elevation as their most important findings, while acknowledging the potentially influential roles of migration and demographic factors in producing this relationship.

Scholars generally agree that, across languages, the relationship between particular sounds and the meaning of words is arbitrary. In this article the authors test this assumption, seeking patterned associations between sound and meaning in the basic vocabulary lists of a large, worldwide sample of languages.

The researchers utilize a GIS approach in order to examine the relationship between global linguistic distribution and various cultural and environmental factors. The resulting positive association between political complexity and both latitude and language range leads the researchers to propose that large, politically complex entities exert a homogenizing pressure on language. However, the causal link may also be in the other direction, with possession of common language facilitating the creation of more complex political institutions.

This study examines whether language construction, specifically the number of consonant-vowel syllables, will be related to the environment and literacy of a society. Empirical analysis suggests that consonant-vowel syllables are more common in warmer climates and less common in written languages.

Munroe and Fought attempt to add new perspective to Ember and Ember's (2007) assertion that certain environmental features help to predict mean sonority levels in speech. This article discusses the other possible elements such as word length that might raise the level of communicative efficiency.

This article adds nuanced findings to the previous generalization that high sonority of the vowel explains its more frequent use in warmer climates. The authors find that “speakers in warm-climate languages make more use of the so-called “sonorant” consonants, that is, consonants with some of the qualities of vowels” (123).

This article focuses on environmental and social explainations for variations in sonority. As expected, results suggest that climate, vegetation density, and sexuality are associated with sonority.

This article examines the universal tendency for languages, regardless of their historical relationships, to develop similar words for mother and father on the basis of nursery forms. Findings suggest that Ma, Na, Pa, and Ta are significantly more common sound classes denoting the mother or father.

This article presents a reanalysis of a previous study on language rhythm and consonant-vowel syllables by Ember and Ember (2000). Communicative efficiency, climate, baby-holding, literacy, and mean number of syllables per word were all considered as factors in consonant-vowel syllable use.