Geography & Voice

Each individual language has a few number of sound units (phonemes) and research suggests geography may affect which phoneme's usage become commonplace.

The ejective consonant (e.g. "P" or "K") phoneme exists in ~20% of the languages. Of 500+ languages  studied, research shows that languages spoken at higher elevations were more likely to use ejective consonants. This may be because lower air pressure eases the burst of air characteristic of this phoneme.

Detect Strength Through Voice

The Proceedings of the Royal Society published a study that argues people can accurately judge a man’s strength from his voice.

Scientists asked undergraduates to listen to recordings of men from a variety of cultures. They found that subjects could accurately predict upper body strength based on voice alone - even when that voice was from an unfamiliar culture.