Our Brains “Adjust” to Focus on Sounds from Various Directions

Many mammals, such as dogs, cats, and deer, possess the ability to direct their hearing. Humans lost this capability around 25 million years ago. Nonetheless, new findings suggest that although we lack these physical ear adjustments, our brains have developed compensatory skills to discern the most intense sounds in particular directions.

This study utilized mobile EEG to observe brain electrical activity as participants moved. Previously, EEG techniques involved participants sitting still with electrodes attached to their scalps. However, advancements in lighter, wireless EEG technology now enable measurements of brain activity during movement, creating links between behavior and brain function.

Research indicates that movement significantly influences brain function. “Active exploration enhances perception, fosters spatial mapping, and integrates multisensory information into a cohesive spatial awareness,” says Maren Schmidt Kassow from Goethe University in Frankfurt, Germany, who was not part of this study. “Cognition is fundamentally tied to behavior.”

Studies from Barbara Handel at the University of Würzburg, Germany, demonstrate that walking improves visual information processing, increasing the likelihood of noticing nearby objects. This enhancement typically diminishes when one is stationary. Her team has found that a similar principle applies to auditory perception; the brain continuously adjusts its focus to prioritize the most salient sounds.

During the experiment, 35 participants were outfitted with mobile EEG and motion sensors and instructed to navigate a figure-eight path while listening to a continuous audio stream through in-ear headphones.

The EEG data revealed significant boosts in auditory processing when participants moved compared to when they were standing still. As they turned, their brains further adapted, prioritizing sounds from the direction they were facing. Continuously along the path, the brain’s focus shifted from side to side as they turned, either panning from one speaker to another or physically orienting towards the sound source.

Team member Liyu Cao from Jiang Province, Hangzhou, China, speculates that this internal ear mobility may be an evolutionary adaptation for enhanced safety. “This could facilitate quicker reaction times and safer navigation in changing environments,” he states.

The findings could lead to advancements in filtering background noise based on a person’s walking direction, thereby improving navigational aids for visually impaired individuals and enhancing hearing aid functionality, according to Haendel.

Moreover, this research could shed light on why exercising outdoors seems to confer greater benefits for brain health and cognitive function compared to activities performed on treadmills or stationary bikes. “Movement dynamics extend beyond just muscle activity,” Handel remarks. “Your brain adapts not only how you move but also how it functions. It’s about harnessing that interaction for optimal performance.”