The relationship between the senses is more complex than it appears in our daily lives, as each sense does not work in isolation from the others, but rather they overlap in a way that affects our perception of the world around us.
Among these relationships, the relationship between hearing and sight stands out as one of the areas that most interests researchers in understanding how one sense can enhance or weaken another.
A new scientific study reveals that opening the eyes may help improve hearing ability more than many people assume.
This finding challenges the common belief that closing the eyes enhances auditory focus by reducing visual distractions, as evidence suggests that it may be more complex than that.
Researchers at Shanghai Jiao Tong University in China conducted a series of experiments to test the relationship between vision and hearing, involving 25 volunteers who were asked to distinguish specific sounds amidst a high background noise of 70 decibels, under different visual conditions: closing their eyes, looking at a blank screen, a still image, or a video clip associated with the sound.
The results showed that participants' performance improved significantly when their eyes were open, compared to when they were closed. The type of visual input also proved to play a significant role in hearing accuracy.
When their eyes were closed, participants needed the sound to be about 1.32 decibels louder than the reference level to hear it. However, when viewing a still image associated with the sound, they could hear it even at a level about 1.6 decibels lower. Watching a video clip associated with the sound produced the best results, lowering the hearing threshold by about 2.98 decibels.
To further explain these results, the researchers used electroencephalography (EEG) recordings to monitor brain activity during the experiment.
It turns out that closing the eyes causes the brain to filter sounds more rigorously, reducing its ability to pick up subtle auditory signals amidst noise. Conversely, visual engagement helps to enhance the integration between what a person sees and hears, thus improving the efficiency of auditory processing.
Researcher Yu Huang says that closing your eyes, although it may seem like a way to increase concentration, can be counterproductive in noisy environments because it reduces the brain's ability to separate the target sound from the surrounding noise.
The study also indicates that the correlation between visual and auditory information plays a key role, as watching scenes associated with sound may prompt the brain to enhance its auditory perception and link it to the visual context.
However, the findings do not negate the fact that closing the eyes may be beneficial in some quiet environments for improving auditory focus, as previous research suggests. But in today's noisy world, it appears that opening the eyes and engaging visually may be more effective in supporting hearing.
The results were published in the Journal of the Acoustical Society of America.
