Why do we make noises like ‘oof’ when we lift something or bump into furniture?

A: When you physically exert while doing a task, you may also briefly hold your breath, releasing it as the effort eases. Your body may also contract the muscles around the trunk, making the torso more rigid and giving your arms and legs a more stable base from which to work. When the trunk stiffens, the abdominal muscles brace while briefly holding or restricting the breath. When you release that pressure, air is forced through the partly closed vocal cords, producing a grunt that sounds like ‘oof’.

This said, the noise you make after bumping into furniture has a different origin. A sudden impact, like stubbing your toe or hitting your shin against a wooden beam, prompts the nervous system to respond quickly. You might gasp, tense your muscles, pull away, and vocalise before you have actually decided to do any of these things. A sound like ‘ow’ or ‘ah’ is thus part of the body’s startle response.

The exact sound is not automatic. People learn to react a certain way from those around them, so those speaking different languages and from cultures exclaim somewhat differently.