Altitude May Affect the Way Language Is Spoken

http://www.sciencedaily.com/releases/2013/06/130612173332.htm
The results show a strong 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. The relationship is difficult to explain by other factors, according to Everett.

"I was really surprised when I looked at the data and saw that it correlated so well," Everett says. "It really does not rely very much on my interpretation, the evidence of a relationship between altitude and language is there."

"Ejectives are produced by creating a pocket of air in the pharynx then compressing it." Everett says. "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."

To make these sounds, the body uses air that is not pulmonic, this may reduce the amount of air exhaled from the lungs and decrease dehydration in high altitudes, the study suggests.
Previous studies have shown that Tibetan people breathe at a faster rate than other high altitude populations. This is believed to be an adaptation to the climate and results in a reduction of the effects of hypoxia in high altitude.