Enlarge image

Patterns in Diversity: Languages of the World (symbolic image)

Photo: atakan / Getty Images

The world record for the "quietest" language is held by the northwest coast of North America. Indigenous culture in the cool Pacific climate has settled on words with consonants strung together, such as mosquito in the Salish language Nuxalk: "pk'm". Languages from Oceania or West Africa, on the other hand, sound particularly "loud": There, vowels are clustered with consonants in quick succession, as in the Yoruba word for butterfly: "labalábá".

It is due to the climate in which languages have evolved. This hypothesized connection is confirmed by a new study published in the scientific journal PNAS Nexus. To put it simply, languages in warmer regions are louder than those in colder regions," explained linguist Søren Wichmann from Kiel University, who wrote the paper together with three colleagues from Nankai University in Tianjin, China.

"Loud" or "quiet" are described by the technical term sonority. To do this, the researchers used a scale from 1 for voiceless clicks or plosive sounds such as K, in which the flow of breath is blocked, to 17 for open vowels such as A. In this way, numerical values could be assigned to the 5293 languages whose basic vocabulary is recorded in the Automated Similarity Judgment Program database. Together with temperature data for the respective place of origin, a clear statistical correlation emerged: the average sonority is highest around the equator.

Vocabulary as a climate archive

There are exceptions. For example, in rather warm regions of Central America or on the Southeast Asian mainland, languages with rather low sonority were found. According to Wichmann, this shows the effect of language development that has been delayed over centuries or millennia. The vocabulary could also be seen as a kind of climate archive for the regions of origin.

The explanation for the climate effect is simple: In dry, cold air, the vibration of the vocal cords, which is necessary for the production of voiced sounds, is more difficult, according to the linguist. Warm air, on the other hand, absorbs the high-frequency energy of voiceless sounds – they then sound even less.