Ever shushed the people in your car or turned down the music when you’re trying to merge into traffic—and then felt completely insane? Why would a quiet car help you see better?

It’s not that crazy, actually—your instinct is mimicking a subconscious brain response that helps you focus on visual tasks, research from Sweden suggests.

Related: 5 Brain Tricks That Will Make You More Successful 

After performing MRI tests on 32 participants, the researchers discovered that when people were focusing on something visual, the responsiveness of their auditory nerves—which enable you to hear—decreased.

That means your brain actually “turns down” your hearing so you don’t become distracted by sounds when you need to concentrate on what you see, says lead researcher Patrik Sörqvist, Ph.D. It’s your brain’s way of prioritizing tasks.

And if your subconscious response winds up not being enough to help you focus, your instinct kicks in to turn down the sound on your own. 

Related: The Men’s Health Big Book Of Uncommon Knowledge—Thousands Of DIY Tips, how-To articles, and Awesome Skills Every Modern Man Must Master

So if background noise like music doesn’t bug you when you need to focus, simply thank your brain for doing its job.

But if you find that you’re often distracted when you’re trying to zero in on a visual task, consider cutting the chatter, tunes, and background noise to give yourself a concentration boost.