Stochastic auditory noise enhances cardiac coherence evoked by slow-tempo music: preliminary findings

Heart rate variability (HRV) coherence near 0.1 Hz has been proposed as a sensitive marker of autonomic regulation and stress resilience. Slow-tempo music has been associated with enhanced parasympathetic activity, and the stochastic resonance framework suggests that controlled noise may optimize weak physiological signals. This study examined whether embedding auditory noise into slow-tempo music could enhance HRV coherence.

Twelve healthy volunteers underwent electrocardiogram (ECG) and electroencephalogram (EEG) recordings while listening to slow-tempo instrumental music alone and with superimposed white noise at varying intensities. HRV coherence was quantified using spectral concentration around 0.1 Hz. Analyses compared music-only, zero noise (ZN), optimal noise (ON), and high noise (HN) conditions.

Music alone progressively increased HRV coherence, with a tendency to stabilize around ∼1800 s. When music was combined with noise, HRV coherence showed a pattern consistent with an inverted-U: intermediate noise levels tended to produce higher coherence, whereas ZN and HN conditions were associated with reduced synchronization. Individual variability was evident, with each participant displaying a unique ON level. EEG results showed increased alpha activity, particularly in right-lateralized regions, consistent with relaxation states reported in the literature.

Embedding noise into slow-tempo music selectively amplified HRV coherence near 0.1 Hz, consistent with stochastic resonance. These findings suggest that noise-modulated music may serve as a low-cost, accessible complementary approach to strengthen autonomic regulation and stress regulation.