The hotter the heat, the more we raise our voices. And, consequently, there are languages that are more strident than others, depending on the climate. This has been investigated and corroborated by a team of linguists led by Dr. Soren Wichmann, from the University of Kiel, whose study indicates that the average ambient temperature influences the volume of certain speech sounds. "In general, languages from warmer regions are noisier than those from colder regions," says this expert, whose research is published in PNAS Nexus.
The basic idea behind the study is that we are surrounded by air when we speak and listen. Spoken words are transmitted through the air in the form of sound waves. Therefore, the physical properties of air influence the ease with which speech is produced and heard. "On the one hand, the dryness of cold air poses a challenge to the production of voiced sounds, which require vibration of the vocal folds. On the other hand, warm air tends to limit dull sounds by absorbing their high-frequency energy," explains Dr. Wichmann in a statement.
These factors could favor higher volume of certain speech sounds in warmer climates, known in scientific terms as loudness. Wichmann and his colleagues used the Automated Similarity Judgment Program (ASJP) database to test whether these factors really have an effect on language development. It currently contains the basic vocabulary of 5,293 languages and is constantly being expanded with the support of the ROOTS Cluster of Excellence.
Wichmann and his colleagues found that languages found around the equator in particular have a high average voicing, while languages from Oceania and Africa have the correspondingly highest rate. In contrast, the world record for low sonority belongs to the Salish languages of the northwest coast of North America.
However, there are some exceptions to this trend. For example, some languages from Central America and continental Southeast Asia have a fairly low average sound, although they are spoken in very warm regions.
"Overall, however, we were able to establish a clear relationship between the average loudness of the language families and the average annual temperature," emphasizes Wichmann. The exceptions suggest that the effects of temperature on sonority develop only slowly and only shape the sounds of a language over centuries or even millennia.
Scientists are currently intensely debating the extent to which the environment influences languages. "For a long time, research assumed that linguistic structures are autonomous and are not influenced in any way by the social or natural environment. More recent studies, including ours, are beginning to question this," says the study coordinator.
Studies like this could also open new paths towards knowledge of human societies, for example on the topic of migration. "If languages adapt to their environment in a slow process that lasts thousands of years, then they contain some clues about the environment of their predecessor languages," says the Kiel linguist.
