Supplementary Material for: Hypertension Screening Using Acoustic Analysis and Machine Learning of Random Speech Samples: A Feasibility Study

Background: Hypertension is the leading risk factor for cardiovascular disorders. Early detection and initiation of treatment have been identified as the most effective ways to reduce the burden of hypertension. The most common method for detecting hypertension is blood pressure measurement, typically performed with cuff-based devices, where systolic pressure (SBP) and diastolic pressure (DBP) are measured through Korotkoff sounds. Although this method is accurate and non-invasive, it requires technical expertise and is often inaccessible in rural and remote areas. Objective: In this study, we investigated the feasibility of using overt speech (random speech corpora) through multiple short recordings for hypertension screening based on two hypertension guidelines: 1) SBP ≥ 135 mmHg OR DBP ≥ 85 mmHg, and 2) SBP ≥ 140 mmHg OR DBP ≥ 90 mmHg. Methods: We incorporated speech recordings from 573 participants (197 women) with diverse ages and body-mass-index (BMI) and extracted temporal, spectral, and non-linear acoustic features through three different frameworks, all of which are based on classical and boosted machine learning models. The models were evaluated using a leave-one-subject-out (LOSO) cross-validation scheme. Results: Our proposed pipeline achieved a balanced accuracy (BACC) of 61% for males and 70% for females under the relaxed criterion (SBP ≥ 135 OR DBP ≥ 85), and a BACC of 71% for males and 78% for females under the stricter EHS guidelines (SBP ≥ 140 OR DBP ≥ 90). Conclusions: These results demonstrate the potential of employing overt speech alongside acoustic analysis for hypertension screening.