Mel-frequency cepstral coefficients and spectral features directly drive micro-level autonomic reflexes during brief respiration practices
Jung-tzu Chang, Zai‐Fu Yao
October 23, 2026 preprint DOI: 10.31234/osf.io/5v7y3_v1 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Within-subject experimental study Randomized |
|---|---|
| Sample size | 21 |
| Population | Meditation-naïve female university students |
| Duration | 13 sessions of 4 minutes and 5 seconds each |
| Measures | pulse rate variability (PRV), electrodermal activity (EDA) |
| Key findings | Blood pressure dropped robustly regardless of audio condition, which the authors say confirms the efficacy of a single bout of spontaneous breath awareness. They further report that electrodermal activity and pulse rate variability were acutely sensitive to fine-grained acoustic features, specifically MFCCs, and that physiological coupling patterns reorganized depending on acoustic context, leading them to argue that acoustic parameters are independent modulators of autonomic reflexes rather than a neutral delivery medium. |
Abstract
While digital health platforms increasingly deliver guided mindful breathing interventions via audio, the specific acoustic properties of the guidance are fundamentally ignored as potential active ingredients. This within-subject study implemented an unprecedented high-density experimental design to investigate how distinct, computationally engineered acoustic features (e.g., pitch, zero-crossing rate, natural background sounds) modulate acute cardiovascular, respiratory, and autonomic responses. To rigorously eliminate sex-related physiological variance, 21 meditation-naïve female university students completed 13 randomized audio sessions of a standardized 4-minute-and-5-second guided breathing practice (yielding 273 high-density recording epochs). Multiparametric biosignals, including pulse rate variability (PRV), respiratory dynamics, and electrodermal activity (EDA), were continuously recorded. Results demonstrated a robust reduction in blood pressure independent of audio conditions, confirming the fundamental efficacy of a single bout of spontaneous breath awareness. However, high-resolution analyses revealed a highly modular architecture where peripheralautonomic indices (EDA and PRV) were acutely sensitive to fine-grained acoustic features, specifically Mel-frequency cepstral coefficients (MFCCs). Furthermore, physiological coupling patterns reorganized dynamically depending strictly on the acoustic context. These indings fundamentally challenge the assumption that meditation audio is a neutral delivery medium, establishing acoustic parameters as potent, independent modulators of human autonomic reflexes for future digital therapeutics.