Decoding the cognitive burden of hearing loss through real-world biomarker discovery using EmbracePlus

Identifying objective physiological markers of listening effort, stress, and fatigue in daily life with wearable technology

Executive Summary

• Study approach: Eriksholm Research Centre deploys the EmbracePlus wearable in real-world settings to continuously capture physiological biomarkers (heart rate, electrodermal activity, skin temperature, and activity), alongside self-reported listening experiences and environmental acoustic data.
• Translational relevance: Hearing loss has cognitive consequences and is linked to brain structure changes and increased dementia risk. Yet, objective and real-world measures of the cognitive consequences of hearing loss, such as listening-related stress and fatigue, remain limited. Wearable technology that enables high compliance in older populations is critical for generating reliable longitudinal data, particularly in conditions associated with low dexterity, such as Alzheimer’s or Parkinson’s disease, where continuous objective measures are lacking.
• Early insights: Findings show that stress, measured as a change in heart rate in response to challenging listening situations, depends on personality traits. This emphasizes the need for more personalized hearing care. Moreover, preliminary findings show that experiences of listening effort and fatigue can be predicted by objective data combining several physiological signals from EmbracePlus with real-world acoustic context.
• Impact: The integration of wearable physiological data with real-world contextual data enables the identification of objective markers of listening effort and fatigue, and the development of meaningful real-world endpoints, particularly where continuous, ecologically valid measures have traditionally been lacking. This provides a framework for using wearable technology in older populations to quantify the health benefits of hearing loss interventions and treatments.

Hearing loss as a neurological and public health condition

Hearing loss is no longer viewed solely as a sensory impairment, but as a whole-system condition with significant implications for brain health, cognition, and population-level outcomes (Livingston et al., 2020; WHO, 2021).

According to the World Health Organization (WHO), over 430 million people worldwide live with disabling hearing loss, a number projected to exceed 700 million by 2050, highlighting its growing public health impact (WHO, 2021).

Emerging evidence links hearing loss to structural and functional changes in the brain, including atrophy in auditory and frontotemporal regions and disruption of cognitive control networks, driven in part by increased listening effort and reduced sensory input (Peelle & Wingfield, 2016). This increased cognitive demand places sustained strain on neural systems and may contribute to accelerated cognitive decline over time.

The Lancet Commission report identifies hearing loss as one of 14 modifiable risk factors for dementia, together accounting for approximately 45% of cases worldwide, with evidence showing that individuals with untreated hearing loss have a significantly higher risk of developing dementia (Livingston et al., 2024). Proposed mechanisms include chronic cognitive overload, reduced social engagement and isolation, and shared neurodegenerative pathways. Importantly, the report also highlights that use of hearing aids may help mitigate this risk, suggesting that effective treatment of hearing impairment could play a role in dementia prevention (Livingston et al., 2020).

Beyond its neurological impact, untreated hearing loss is associated with broader health challenges, including increased stress and fatigue, depression and anxiety, and reduced physical and social participation. The WHO emphasizes that untreated hearing loss carries substantial societal and economic costs, affecting healthcare systems, education, and productivity at scale (WHO, 2021).

Despite these wide-ranging effects, key aspects of the condition, particularly daily stress, listening effort, and fatigue, remain difficult to measure using traditional clinical approaches, limiting the ability to fully understand and address its real-world impact.

A measurement gap with implications beyond audiology

Traditional audiology focuses on hearing thresholds and speech perception in controlled environments (Billings et al., 2023). While valuable, these metrics fail to capture the real-world physiological and cognitive burden of hearing loss.

This limitation has implications far beyond hearing care. For neuroscience and aging research, there is a need for objective, continuous markers of cognitive load and stress. For pharmaceutical development, particularly in areas such as neurodegeneration, mental health, and fatigue-related conditions, there is increasing demand for digital biomarkers that reflect real-world function.

Hearing loss provides a compelling model system: a condition where environmental complexity, cognitive effort, and physiological stress intersect in measurable ways.

The Eriksholm Research Centre and study

The Eriksholm Research Centre is a global leader in audiological research, dedicated to translating scientific discoveries into meaningful improvements in hearing care. As part of Oticon, Eriksholm works in close collaboration with academic institutions, clinicians, and end-users to ensure that scientific insights are applied in solutions that directly benefit people with hearing loss.

Jeppe Christensen, Principal Scientist at Eriksholm, explains that “Eriksholm pursues audiological discoveries with the potential to significantly improve the lives of people with hearing loss in future hearing care… our scientific insights are applied in solutions and technological innovations across the whole hearing care journey.”

Working at the intersection of academia, clinical practice, and industry, Eriksholm is uniquely positioned to explore how real-world data can transform understanding of hearing loss and its broader health implications.

To address the gap between laboratory findings and real-world experience, Eriksholm pursued wearable technology to investigate physiological correlations of listening effort, stress, and fatigue in everyday life.

The study focused on hearing aid users, many of whom were older adults, a population at increased risk of hearing loss, social isolation, and cognitive decline. Participants were asked to wear Empatica’s EmbracePlus device continuously in their daily environments while also reporting their listening experiences using experience sampling methods. This approach enables the capture of high-resolution, real-world data that reflects the true complexity of everyday listening, moving beyond the limitations of controlled laboratory testing. As the team notes:

“In order to push audiological innovation, it is crucial to obtain audiological insights from the real world in contrast to relying only on laboratory test outcomes, which are typically not ecologically valid. A wearable, like the EmbracePlus, can help us gather “passive sensing” data about how hearing-aid users are experiencing their everyday listening environments, capturing continuous physiological responses to real-world acoustic demands without adding burden or requiring active input from participants.”

The study utilized the EmbracePlus wearable to collect multimodal physiological data, including:

• Heart rate
• Electrodermal activity (EDA)
• Skin temperature
• Physical activity

These signals were analyzed as time-series data and integrated with:

• Self-reported listening effort and fatigue
• Acoustic features of the surrounding environment

This multimodal framework allows researchers to model how external demands translate into internal physiological responses.

To support this, the team recently published a study that establishes how heart rate recorded with an Empatica E4 device can be used to estimate listening effort as a less obtrusive alternative to traditional pupillometry (Christensen et al., 2026).

Early insights from the research

Newly published findings from the study demonstrate the potential of combining wearable data with environmental context.

The team recently published a study showing how individuals with higher conscientiousness report more listening effort as environments get louder and show greater increases in heart rate when environments get clearer (better SNR), possibly reflecting stronger listening engagement or motivation (Micula et al., 2026). Such insights are important for developing personalized hearing care beyond one-size-fits-all solutions.

We also asked the team if any other preliminary findings could be shared. “One of our interesting and novel results shows that feelings of listening-related effort and fatigue in daily life can be predicted by combining measures of the ambient acoustics with wearable data from EmbracePlus devices, namely, heart rate, skin temperature, and electrodermal activity.” This represents a significant advance in the ability to quantify subjective experiences using objective biomarkers, opening the door to new types of outcome measures.

The value of Empatica’s technology when monitoring older populations

Ensuring consistent device use is critical for long-term studies, particularly in older populations, who are most affected by hearing loss and most relevant for research into age-related neurological conditions.

The Eriksholm team previously faced challenges with earlier devices: “Compliance was not great… participants had to turn on the device themselves each morning… This resulted in several days without any recordings.”

With EmbracePlus, this barrier was removed: “This issue is now solved with the EmbracePlus devices that are always on.”

This improvement is particularly significant in the context of neurodegenerative research, where study populations often include individuals with cognitive or motor impairments. In such settings, even small usability barriers can lead to substantial data loss. Passive, always-on systems, therefore, play a critical role in enabling high compliance, continuous monitoring, and reliable longitudinal datasets.

The promise of digital health technology

Wearable technology is driving a shift from static, clinic-based assessments to dynamic, real-world monitoring of health and disease. In the context of hearing loss, this enables researchers to move beyond controlled environments and capture how individuals truly experience listening in everyday life.

As Jeppe Christensen highlights, “Wearable data is crucial for obtaining real-world evidence of the effectiveness of hearing loss treatments. I believe this will play an increasingly important role in the future, as research consistently shows that hearing loss and treatment thereof influence general health and wellbeing.”

By enabling continuous, objective measurement of physiological responses, wearable technologies like EmbracePlus provide a powerful tool to uncover the hidden burden of hearing loss, including stress, fatigue, and cognitive effort. This creates new opportunities to:

• Understand brain–body interactions in real-world settings
• Identify early markers of cognitive decline
• Generate robust, real-world endpoints for research and clinical development

Crucially, this approach offers a scalable pathway to generate high-quality data in populations that have traditionally been difficult to study, particularly older adults. By utilizing high-compliance wearables for real-world monitoring, researchers can begin to quantify the health benefits of interventions and better understand how treatments influence physiological outcomes over time.

Looking ahead, Eriksholm’s future research will build on this foundation by using wearable data to evaluate the objective, health-related benefits of hearing aid technologies, including whether more advanced hearing-aid solutions (such as active noise reduction) can reduce stress and improve physiological outcomes compared to simpler hearing aids. These insights have the potential to inform more personalized and effective treatment strategies, with implications not only for hearing care but also for broader areas of healthcare, neuroscience, and aging.

The team also emphasizes that while wearable technology unlocks new possibilities, it requires careful implementation: “Make sure to have concrete hypotheses and a solid plan for data management and analysis. Wearable technology will deliver lots of new data; it can be overwhelming to manage without a clear plan.”

As research in this field continues to evolve, the integration of wearable data into clinical and research workflows is expected to play an increasingly important role in advancing both scientific understanding and patient outcomes.