Blind people can size you up just by hearing you

It’s not quite Daredevil levels of perception, but a new study shows that blind people can size up men just by listening to the sound of their voices. We tend to think deeper voices belong to taller people, but is this because of what we see or what we hear? To find out, researchers recruited 68 blind men and women and 23 sighted people and asked them to listen to recordings of pairs of 30 men uttering vowel sounds like a, e, i, o, and u, as heard in the video above. (The study used only vowel sounds so that only pitch would be used to judge height as opposed to cadence or pronunciation.) The blind volunteers were about 56% accurate at picking the larger male, only slightly less accurate than the sighted volunteers. This suggests that associating sound with body size could be a skill humans are born with, or that blind people can learn it through other means, such as the heights from which they hear voices the team reports online today in Biology Letters. And although past studies have shown that the blind can outperform the sighted at using sound to judge location or at discriminating pitches, these skills don’t appear to give the blind an advantage in sizing people up.

(Video credit: AAAS/Science)