Don’t Close Your Eyes to Hear Better: New Study Reveals Surprising Listening Trick

The instinct to close your eyes when trying to hear in a noisy environment is common. But does this actually assist? Recent research challenges that long-held belief, suggesting that shutting your eyes may, in fact, develop it harder to discern faint sounds when background noise is present. The findings, published by researchers at Shanghai Jiao Tong University, upend conventional wisdom about optimizing our senses for better hearing.

How Visual Input Impacts Auditory Perception

The study, led by Yu Huang, PhD, an associate professor at the Institute of Vibration, Shock, and Noise at Shanghai Jiao Tong University in China, demonstrates that our brains rely on visual cues to effectively filter and process sound. “The key takeaway is: Forget the old wisdom,” Dr. Huang explains. “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.”

Researchers found that 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 perceive them with their eyes closed compared to when they were open – a phenomenon researchers termed “raising the threshold” for noise perception. This suggests that visual information plays a crucial role in our brain’s ability to process auditory input, particularly in challenging environments.

The Brain’s “Critical Neural State” and Sensory Filtering

The study delved into the neurological mechanisms behind this effect. Researchers recorded brain activity from 27 participants even as they listened to sounds, both with and without masking noise. They discovered that closing the eyes shifts the brain into a processing state that aggressively filters incoming information. This over-filtering suppresses not only background noise but as well faint target sounds, making them harder to detect. Conversely, opening the eyes – especially when accompanied by dynamic visual cues – shifts the brain towards a more excitable and externally focused state, reducing this over-filtering effect.

The researchers identified a “critical neural state” – a balance between stability and responsiveness – that appears to be key to this process. Visual input helps maintain this optimal state, allowing the brain to effectively process both noise and faint sounds. This finding builds on earlier research suggesting that the brain’s reduced visual load in quiet environments can free up cognitive resources for auditory processing, enhancing attention, memory, and speech perception. Brain exercises can also help with this.

What the Study Actually Showed – and Didn’t Show

The study involved 25 young adults identifying real-world sounds (canoe paddling, drum playing, lark chirping, train movement, and typing) hidden within 70-decibel pink noise under various visual conditions: eyes closed, eyes open looking at nothing, eyes open with a static image, or eyes open with a moving video related to the sound. The results consistently showed that visual cues – particularly dynamic visuals – improved sound detection. A static image lowered the detection threshold by about 1.6 dB, while a moving video lowered it by approximately 3 dB.

However, it’s essential to note the study’s limitations. The participant group consisted solely of young adults with normal hearing. The findings may not be generalizable to older adults or individuals with hearing impairments. The study focused on relatively simple auditory tasks. The impact of visual input on more complex listening scenarios, such as conversations in crowded rooms, remains to be fully understood. As noted by Malte Wöstmann, PhD, a postdoctoral fellow at the University of Lübeck’s Institute of Psychology, the study demonstrates that closing the eyes isn’t simply enhancing auditory attention, but induces more versatile effects. Dr. Wöstmann’s research focuses on the connection between auditory attention, visual input, and brain processing.

Quiet Spaces: When Closing Your Eyes Still Makes Sense

Interestingly, the researchers emphasize that the findings do not apply to quiet environments. In the absence of overwhelming background noise, closing your eyes can still enhance auditory perception by reducing visual distractions and allowing the brain to focus more intently on faint sounds. This aligns with previous research demonstrating that eye closure increases brain activity linked to attention and sensory filtering.

Implications for Real-World Applications

The study’s findings have potential implications for various real-world applications. Dr. Huang suggests that the research could inform the design of workspaces, such as control rooms or cockpits, to optimize sensory input and improve situational awareness. It could also contribute to the development of more effective hearing aids that leverage visual cues to enhance sound processing. Daniel Troast, AuD, an audiologist and hearing health advocate at HearUSA, highlights the importance of utilizing all available cues in complex environments, as the brain builds a comprehensive picture of the surroundings by combining information from multiple senses. Dr. Troast emphasizes that limiting input to a single sense can hinder accurate interpretation of the environment.

What’s Next for Sensory Perception Research?

Dr. Huang and his team are eager to translate these lab-based neuroscience findings into practical tools that improve people’s daily sensory experiences and safety. Future research will likely explore the optimal types of visual cues for enhancing auditory perception in different environments and investigate the potential benefits for individuals with hearing loss. Further studies are also needed to determine whether these findings extend to other sensory modalities, such as the interaction between touch and vision. The researchers also plan to investigate how these principles can be applied to improve the design of assistive technologies and create more immersive and effective sensory experiences.