Do we listen with our eyes? A behavioural study is the first to suggest that the simple, rhythmic hand movements people often make while speaking affect fundamental aspects of how their words are perceived.
Hans Rutger Bosker at the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands, and David Peeters at Tilburg University, also in the Netherlands, asked volunteers to watch videos of a speaker who used up and down hand movements called beat gestures while talking. Study participants then reported the syllables that the speaker had stressed, or assessed vowel duration.
Participants were more likely to hear emphasis on a syllable that coincided with a beat gesture than on a syllable that did not. Surprisingly, the vowels in gesture-linked syllables also seemed shorter to listeners. Both effects were subtle, but have the potential to drastically alter the meaning of an entire sentence — consider the shift in the emphasis from ‘OB-ject’ to ‘ob-JECT’, or the truncation of the vowel sound from ‘code’ to ‘coat’.
The study bolsters emerging theories of word recognition, which suggest that language comprehension is a broad synthesis of the senses.