Staying on Mountains Causes People to Speak Differently

Can staying on mountains make a difference to the way we speak? It is true that when we stay on mountains, the way certain words sound is different.
Languages with guttural bursts of sound that have "ejective" consonants are found to be spoken in communities which live on mountains. Experts reason that the effort to produce ejectives in thinner mountain air is much less, which is why language is spoken in such a manner.
Researchers discovered that close to 80% of languages with ejectives were spoken in areas within 500 kilometres of a region of high elevation, an altitude higher than 1500 meters above sea level. This was found to be true across all continents. 
"This is really strong evidence that geography does influence phonology - the sound system of languages," said lead scientist Dr Caleb Everett, from the University of Miami. 
"Ejectives are produced by creating a pocket of air in the pharynx then compressing it. 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."
Source:Univ.of Miami