Preliminary Findings on Effect of Stress on Breathing Sound Signal

Abstract

On the onset of the Covid-19 pandemic, announced by WHO on March 2020, the global prevalence estimates for stress were 37%.  Extreme stress causes psychological problems in workers such as anxiety and depression, burnout, and decreased productivity.  The research among healthy adults has shown that slow breathing significantly reduces psychological stress.  However, the breath ratios of inhale versus exhale do not have a significant differential effect on stress reduction. The goal of this study was to quantify sound power of the breathing sound signals of adults, induced by stressful mental workload.  Eighteen adults participated in the study.  Thirty-six samples of breathing sound signals were captured for normal breathing, and after the participants had undergone three Stressors - Stroop, Trail Marking, and Mental Arithmetic tests. The acquired breathing sound signals were then analysed to obtain power spectral density (PSD). From PSD, the magnitude and the frequency of sound power of the breathing signals were determined.  For normal breathings, the magnitude of sound power of male and female participants decreases the same pattern as the frequency of the breathing sound signal increases.  However, after they had undergone the Stressors, the magnitude of sound power of the breathing signals of the female participants spikes between frequency 1200 Hz and 2000 Hz.  In conclusion, the male participants are indifference to the stressful mental workload imposed to them, while the female participants were susceptible to stress at higher frequency.