New Research: Closing Eyes to Hear Better Can Impair Sound Detection in Noisy Environments
New research suggests that the common reflex of closing eyes to hear better actually impairs the ability to detect faint sounds in noisy environments. While this strategy may be effective in silent rooms, a study published in JASA indicates it can be counterproductive amid background noise.
The Experiment
Researchers from Shanghai Jiao Tong University conducted experiments where volunteers listened to sounds through headphones in a noisy setting, adjusting the volume until the sounds were barely audible. Tests were performed under four conditions: eyes closed, eyes open with a blank screen, looking at a still photo, and watching a dynamic video corresponding to the sound.
Counterintuitive Results and Brain Activity
The findings revealed that closing one's eyes hindered the ability to detect sounds. Conversely, seeing a dynamic video related to the sound significantly improved hearing sensitivity.
Electroencephalography (EEG) monitoring showed that closing eyes induces a state of "neural criticality." This process causes the brain to aggressively over-filter incoming sensory data, thereby suppressing both background noise and the target sound.
Why Visuals Matter
According to author Yu Huang, this internal focus promoted by eye closure works against individuals in noisy soundscapes. In contrast, visual engagement helps to anchor the auditory system to the external world. The research suggests that the brain performs optimally when visual and auditory information are synchronized, for example, seeing a mouth move while hearing a voice.
Specifics and Future Directions
The study emphasizes that these results are specific to noisy environments; in calmer settings, closing eyes might still aid in detecting faint sounds. Future research will explore the effects of incongruent visual and auditory pairings to understand if the visual boost stems from simply having eyes open or if perfect synchronization is required.