Next health frontier? Earbuds may soon monitor our brains

The next frontier in checking on the vital organ's well-being is to utilize technology that millions of people are already using every day, say scientists.

The world-first study found that commercially available earbuds have the capability to detect and classify brain activity — simply by measuring subtle changes in users’ hearing.

An international research team used acoustic sensors in earphones to assess cognitive load — the mental effort that shapes learning, task performance and early cognitive decline.

They say their findings could lead to new ways to improve performance in sectors such as education, aviation, healthcare, user experience design or the armed forces by identifying when people are overwhelmed, or when they have capacity to learn more.

The project was co-led by Dr. Ting Dang, a senior lecturer in digital innovations at the University of Melbourne in Australia, and University College London (UCL) doctoral student Xijia Wei.

They worked with researchers from Nokia Bell Labs at Cambridge University and the University of Washington to design the experiment and collect, analyze and model the data.

“Some commercial earbuds are already being used to track movement and heart rate,” Dr. Dang said.

"Our research shows that soon earbuds may be able to monitor people’s brains.

“Ear-worn devices could be used to reduce mental strain and improve efficiency, safety and overall human-computer interaction.

"They are quietly becoming the next major health platform, with the market expanding quickly and big tech moving rapidly into health.”

The researchers used sensors in commercially available earphones to measure tiny cochlear responses, which indicate strain on the brain and central nervous system.

The team attached a 10-millimeter speaker and sensitive microphone into an earable prototype and designed listening tasks to induce varying levels of cognitive load for the 19 test subjects, aged 20 to 55.

They designed an AI model to categorize the cochlear responses into four levels of cognitive load and used EEG headsets to collect data to validate the findings.

The team found that increased cognitive load led to greater auditory sensitivity, with patterns varying across demographic subgroups, such as age and gender, which may lead to additional opportunities for personalized monitoring.

Dr. Dang added: “This work points to a future where your earbuds become real-time, personalized, cognitive monitors, adjusting lessons to your mental capacity, enhancing productivity, helping workers manage overload, or offering early warnings of brain health issues."

The research team hopes to expand the frequency range of their auditory testing by exploring the use of broadband or wider frequency stimuli.

They say their findings, published in proceedings from the Association for Computing Machinery’s conference on Pervasive and Ubiquitous Computing held at Aalto University, Finland, also need to be validated on larger, more diverse volunteers to ensure the feasibility of large-scale cognitive monitoring.