Effortful Listening Activates Ear Muscles in Hearing Aid Users

When a person with hearing aids concentrates on a single voice in a noisy room, their ears may literally try to move. A new study published in Frontiers in Neuroscience provides the first direct measurement of this “auriculomotor” activity in hearing aid users, finding that the effort of listening in noise is written in the subtle twitches of muscles around the ear.

Measuring the Physical Strain of Listening

Andreas Schroeer, Tanja Biehl, and Matthias Latzel designed an experiment to see if the physical effort of listening could be tracked. They recruited 24 experienced, bilateral hearing aid users with an average age of 64.

The participants were asked to focus on a target podcast under three distinct conditions. The first was a simple task: listening in quiet (SIQ). The other two involved listening to the podcast against a background of spatially distributed noise. In one noisy condition, a specialized noise reduction feature in their hearing aids was active (NR-on). In the most difficult condition, this noise reduction was turned off (NR-off). Participants rated their perceived listening effort after each task, confirming that the three conditions represented a clear ladder of difficulty from easiest (SIQ) to hardest (NR-off).

While the participants listened, the researchers recorded electromyographic (EMG) signals from three muscles. They monitored two auricular muscles—the superior auricular muscle (SAM) above the ear and the posterior auricular muscle (PAM) behind the ear—along with the corrugator supercilii, a facial muscle responsible for frowning.

A Muscle Behind the Ear Tracks Listening Effort

The results, detailed in the paper (DOI: 10.3389/fnins.2026.1838748), showed a distinct physiological signature for listening strain.

Activity in the posterior auricular muscle (PAM) closely followed the pattern of perceived effort. It was lowest during quiet listening, higher when noise reduction was on, and highest when noise reduction was off. The increase from the quiet condition to the most difficult noisy condition was statistically significant. This suggests the small, often-overlooked muscles behind our ears are still recruited during intense auditory focus, potentially as a vestigial reflex to orient the ear.

The corrugator supercilii muscle told a different story. Its activity remained low in the quiet condition but showed a significant, steady increase over time during both noisy scenarios, regardless of whether noise reduction was active. This points to a more generalized stress or cognitive load response—the physical act of frowning—that builds the longer one struggles to hear in noise.

An Unexpected Complication and Future Directions

The study also uncovered a significant challenge for this line of research. The superior auricular muscle (SAM), positioned above the ear, did not respond to task difficulty as hypothesized. Instead, its activity showed a strong and unexpected decrease over the course of the experiment across all conditions. The researchers identify this “time-dependent decrease” as a serious confounding factor that could mask true effects related to listening effort.

This finding makes the study preliminary. Schroeer and colleagues conclude that while auricular muscle activity holds promise as an objective biomarker for listening effort, the protocol must be modified to account for this time drift, and studies with larger participant groups are necessary for confirmation. Future work will need to separate genuine listening-related muscle activation from general fatigue or habitation effects.

Implications for Hearing Health and Device Design

This research opens a new avenue for quantifying the often-exhausting experience of hearing loss. Subjective reports are valuable, but an objective, physiological measure could change clinical practice and device development. If reliably measured, auriculomotor signals could be used to assess how draining different listening environments are for an individual, providing data beyond standard audiograms. This is particularly relevant for conditions like hidden hearing loss, where hearing tests appear normal but understanding speech in noise is impaired.

In the long term, the concept of a “closed-loop” hearing aid becomes more plausible. Such a device could use real-time physiological feedback, like PAM activity, to automatically adjust its settings the moment it detects the user is under auditory strain. This would move beyond pre-programmed settings to a responsive, moment-by-moment optimization of sound. The finding that a facial frown muscle also activates aligns with broader research into how hearing challenges affect overall well-being, similar to studies on stress and heart rate patterns in people with tinnitus.

For now, the study by Schroeer et al. provides a tangible, if complex, link between the cognitive work of listening and our physical bodies. It reminds us that the struggle to hear is not just a mental task but one that can engage ancient muscular systems, offering a new window into the true cost of hearing loss.