Many people believe that closing their eyes improves their hearing. It feels natural to shut one’s eyes when trying to focus on a sound. However, new research shows that this may not be true, especially in noisy environments.

A study published in the Journal of the Acoustical Society of America explored how vision affects hearing. In the experiment, participants were asked to listen for faint sounds of drums, birds chirping or a train, while steady background noise was playing.

The researchers tested several conditions. In one, participants kept their eyes closed. In others, they kept their eyes open while looking at a blank screen, a still image or a video that matched the sound they were hearing. 

The goal was to see how these visual changes affected their ability to detect sounds.

Participants had more difficulty hearing sounds when their eyes were closed. In contrast, performance improved when their eyes were open, especially when they were watching videos related to the sound. 

“We found that, contrary to popular belief, closing one’s eyes actually impairs the ability to detect these sounds,” researcher Yu Huang said.

To understand why this happens, researchers also examined brain activity. They found that closing the eyes shifts the brain to a more inward-focused state where the brain filters incoming information more strongly.

While filtering may seem helpful, it can create problems in noisy environments. The brain may filter out not only the background noise but also the sound a person is trying to hear. This makes it harder to detect faint sounds. 

“In a noisy soundscape, the brain needs to actively separate the signal from the background,” Huang said

When the eyes are open, especially with visuals that match the sound, the brain stays more connected to the external environment. This helps improve how the brain processes sound and makes it easier to pick out important signals. 

The study also suggests that closing the eyes may still be helpful in quiet environments. However, in everyday situations with background noise, keeping eyes open may be more effective.