Altitude Shapes the Sound of Language: Mountains Affect Way We Speak

Your voice can sound differently when you breathe in different mixtures of gases. For example, helium can make your voice sound like a cartoon character's. But what happens when you have to use less effort to speak, like at high altitudes? It turns out that our very language changes. A new study has revealed that there is a link between geographical elevation and the way language is spoken.

In order to examine what effect altitude might have on the languages that are spoken throughout the world, the researchers analyzed the locations of about 600 representative languages of the 7,000 or so languages currently present. More specifically, the researchers examined what linguistic sounds each employed. Ninety-two of them, for example, had ejectives. These sounds are produced by creating a pocket of air in the pharynx then compressing it.

The next step was to compare the languages with their location. Using Google Earth and ArcGIS v. 10.0, the researchers superimposed the locations of these sound systems on the world's landscape to analyze the patterns. It turns out that there was a correlation between high altitude and the presence of ejectives in languages on, or near, five of the six major high altitude regions on Earth where people live.

"This is really strong evidence that geography does influence phonology--the sound system of languages," said Caleb Everett, author of the study, in a news release. "It really does not rely very much on my interpretation, the evidence of a relationship between altitude and language is there."

In fact, the only region with high elevation where languages with ejectives were absent was the large Tibetan plateau and adjacent areas. Yet Everett believes that the people of this region have a unique adaptation to high altitude that may account for this fact.

"Ejectives are produced by creating a pocket of air in the pharynx then compressing it," said Everett in a news release. "Since air pressure decreases with altitude and it takes less effort to compress less dense air, I speculate that it's easier to produce these sounds at high altitude."

The findings not only reveal an interesting pattern in languages, but may allow researchers to gain insight into the evolution of languages. Efforts are ramping up to reconstruct "mother" languages, from which major languages descended. Learning how altitude and geography could affect the creation of languages is a huge step to understanding past languages.

The findings are published in the journal PLOS One.