Vocal tract anatomy influences how languages sound

Research published in PLOS Biology suggests that individual anatomical differences in the vocal tract—including the shape and size of the palate, tongue, and pharynx—play a significant role in how languages sound. While humans compensate for these physical variations to ensure intelligibility, the compensation is imperfect, leaving measurable acoustic traces in vowel pronunciation.

A study led by researchers from the University of Neuchâtel and the University of Zurich analyzed real-time MRI videos of 32 American English speakers. By marking 95 points across the vocal tract in over 3,200 images, the team found that vocal tract shape explains approximately half of the acoustic differences between speakers.

This finding challenges traditional linguistic views that attribute language evolution primarily to cultural processes, often dismissing individual pronunciation differences as mere ‘noise’. The study supports a growing body of research suggesting that human biology continues to influence linguistic evolution even after the capacity for speech has developed.