Measuring negative emotions and stress through acoustic correlates in speech: A systematic review.
Level 2 - randomized trial
Systematic review of experimental and observational laboratory studies (by design analogy).
PubMed 40705747 · doi:10.1371/journal.pone.0328833
What was done
A systematic review was conducted across PubMed, PsycInfo, Web of Science, and Scopus to evaluate acoustic correlates (spectral, prosodic, and voice quality features) for detecting negative emotions, stress, and cognitive load in speech. Inclusion was limited to peer-reviewed studies in healthy adult participants. Thirty-eight articles comprising 39 distinct studies were included.
What was found
The abstract reports qualitative directions without numerical effect sizes or statistics. Prosodic features were the most investigated and accurate markers. Anger was associated with elevated fundamental frequency (F0), increased volume, and faster speech rate. Stress was associated with increased F0 and intensity, and reduced speech duration. Cognitive load correlated with increased F0 and intensity, though F0 findings were less consistent than those for anger and stress. No consistent acoustic markers were identified for fear or anxiety.
Why it matters
This review identifies which vocal features reliably track anger, acute stress, and cognitive load, clarifying acoustic biomarker targets for behavioral, experimental, and remote monitoring applications.
Limits
The abstract reports no numerical effect sizes or pooled statistics. Results are restricted to healthy adults and cannot be assumed to apply to clinical populations. Acoustic analysis did not reliably identify fear or anxiety.
Cited by
- supports Experiencing nervousness or acute anxiety causes a person's vocal pitch to elevate above their natural speaking tone.