In a loud place, you might find yourself instinctively shutting your eyes in order to listen for faint noises. But does it really help?
A new study challenges that common practice, with findings that suggest closing your eyes may make it harder, not easier, to pick out quiet sounds in noisy environments.
“The key takeaway is: Forget the old wisdom,” says an author of the study, Yu Huang, PhD, an associate professor at the Institute of Vibration, Shock, and Noise at Shanghai Jiao Tong University in China.
“Whether you’re trying to detect a vehicle in traffic, or pick out a bird chirp in a windy park, opening your eyes will make your brain far better at picking out faint target sounds from background noise,” Dr. Huang says. “Dynamic visual cues offer the biggest boost, but even just having your eyes open could help.”
Without Visual Information, Our Brains Filter Out Faint Sounds in Noisy Spaces
Researchers set out to analyze whether shutting the eyes improves the ability to detect faint sounds buried in background noise — and if visual information impacts the way the brain processes these sounds.
For the first part of the study, researchers tested how well 25 young adults could identify faint real-world sounds (canoe paddling, drum playing, lark chirping, train moving on tracks, and typing on a keyboard) hidden in background noise (70-decibel pink noise) under different visual conditions: with their eyes closed, eyes open but looking at nothing, eyes open with a static image, or eyes open with a moving video related to the sound.
For the second part of the study, researchers recorded brain activity of another 27 participants while they listened to sounds without masking noise. Scientists measured how close the brain activity was to a “critical neural state” — generally defined as a balance between stability and responsiveness. They also measured brain wave changes as indicators of listening effort and cognitive load, or the amount of mental effort used to process information and complete tasks.
Here’s what they found.
- Participants were less able to detect faint sounds when their eyes were closed. On average, noises had to be 1.32 decibels (dB) louder for participants to hear them with their eyes closed than with them open — what researchers called “raising the threshold” for noise perception.
- Visual information helped make faint sounds easier to hear in noisy environments. When participants got visual cues (images or videos showing the sound source), they detected sounds more easily. For example, seeing a static image related to the sound lowered the detection threshold by about 1.6 dB, while watching a dynamic video lowered the detection threshold by about 3 dB.
- Brain activity showed changes in listening efforts, with eye closure moving the brain into a different processing state that may filter out weak signals along with noise, making faint sounds harder to detect.
Huang says his team was surprised to find visual cues can actually help people detect sounds in noisy environments like crowded spaces or busy streets. But earlier research, he says, focused only on quiet scenarios or ones where people were talking.
The researchers conclude that this effect is driven by that “critical neural” brain state, which allows for stability while adapting to new information.
“When people close their eyes, the brain shifts toward a state that aggressively over-filters incoming information, suppressing faint target sounds alongside background noise in noisy environments,” Huang explains.
“Opening the eyes — especially with relevant dynamic visuals — shifts the brain away from this over-filtering state to a more excitable, externally focused” state, he says.
Closing Your Eyes May Still Improve Hearing in Quiet Scenarios
The idea that shutting your eyes helps improve listening has had some scientific support, with previous studies showing that the act of closing your eyes increases brain activity linked to attention and sensory filtering.
The researchers underscore that the findings don’t apply to a quiet background, where it’s likely that keeping your eyes closed would help you detect faint sounds.
“Without overwhelming background noise, the brain’s reduced visual load frees up cognitive resources for the auditory system. This is why prior research shows that eye closure enhances auditory attention, memory, and speech perception in quiet: It lets the brain focus internally on weak auditory signals without visual distraction,” Huang explains.
How the Findings Could Expand on Listening in Different Environments
The results illustrate how our senses build upon each other to shape real-world perception, notes Daniel Troast, AuD, an audiologist and hearing health advocate at HearUSA based in Winter Garden, Florida.
“The brain builds a picture of the environment by combining information from multiple senses, not just hearing. When input is limited to only one sense, the brain has less information to interpret what’s happening around it,” says Dr. Troast. “In complex environments, it’s important to utilize all of the cues available to you.”
According to Dr. Wöstmann, the use of both behavioral and brain activity testing enhances the validity of the findings — but the use of the criticality concept is less helpful. “Criticality can be considered a rather nonspecific neural signature, such that it is not straightforward to draw mechanistic conclusions.”
In addition, the results may not be generalizable to the broader population, as the participant group was made up of young adults with normal hearing.
Is There Any Real-World Takeaway From These Findings?
While this new evidence doesn’t necessarily point toward specific recommendations for the average person quite yet, Huang says that it could have the potential to be used in real-world design and rehabilitation, including workspaces like control rooms or cockpits, and in future hearing aids.
“We’re eager to build on these results to turn lab-based neuroscience into practical tools that improve people’s daily sensory experience and safety,” he adds.
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