Spontaneous postural adjustments reduce perceived listening effort

• Participants implemented active motor strategies as the SNR increased • They adapted their posture even if this did not affect performance • Postural adjustments reduced listening effort When listening in noise the challenge of segregating target signals from interfering sounds increases cognitive load. Unfavourable signal-to-noise ratios (SNR) worsen speech comprehension and impact on listening effort. To enhance speech comprehension, individuals can adapt postural adjustments (e.g., move their heads and bodies) that increase target signal intensity with respect to interfering sounds. However, it is not clear whether postural adjustments also reduce listening effort. In the present study, we aimed to trigger posture adjustments with changing SNR levels and studied their effects on speech recognition and perceived listening effort. We asked participants to verbally report spoken digits emitted from one of four target locations and embedded in masking noise, delivered at different SNRs. We recorded movements of the head and trunk via a motion-capture system. Crucially, participants completed the task in both a free-posture condition (i.e., they were free to adjust their posture to obtain the most comfortable position for speech recognition) and a still condition (i.e., they maintained a fixed frontal position oriented toward the speakers). We collected measures of accuracy and perceived listening effort. In the free-posture condition, the participants’ movements toward the speakers, albeit minimal, increased as SNR declined. Interestingly, while postural adjustments had no measurable effect on speech recognition, they nonetheless produced small, but measurable, reductions in perceived listening effort. This provides initial evidence that posture adjustments can reduce perceived listening effort even when listening performance remains, in fact, unchanged.