# Assessing effects of vibroacoustic stimulation compared to a guided mindfulness meditation using the biosignal of human speech

## TL;DR

This study explores how speech patterns change after stress-reduction techniques, finding that both meditation and vibroacoustic therapy can reduce stress as measured by vocal quality.

## Contribution

The study introduces speech prosody as a novel, non-invasive biosignal for evaluating stress reduction interventions.

## Key findings

- Groups undergoing meditation and vibroacoustic therapy showed breathier vocal quality post-treatment.
- Control group speech remained tense and less variable in loudness after the session.
- Speech prosody proved effective in distinguishing treatment effects from control.

## Abstract

High stress and low wellbeing pose severe individual, societal and economic threats, and there is a pressing demand for non-invasive stress reduction tools. This exploratory pilot study assessed the efficacy of speech prosody as a biosignal for stress elicitation, when comparing relaxation outcomes of two interventions with a control group.

Thirty participants were divided into three treatment groups; (1) guided mindfulness meditation (2) vibroacoustic intervention (3) control. All participants read aloud a text before and after one 20-min treatment. The sixty readings were assessed using a multi-parametric acoustic-prosodic analysis, and within-speaker differences were compared between the initial and final reading.

Results show groups (1) and (2) spoke with a breathier vocal quality in the second reading, while group (3) speech was tenser and at a lower, less variable loudness.

Results demonstrate speech prosody is a sensitive biomarker for treatment-effect classification and evaluation. Practical limitations and future research perspectives are discussed.