Voice phishing detection compares self-supervised and prosodic features

Comparing Self-Supervised and Domain-Invariant Features for Cross-Domain Voice Phishing Detection

SoundComputation and Language

Summary

Detecting voice phishing is hard because real scam recordings are private and few samples exist. The authors compared two approaches: one uses features that do not change across different settings, and the other uses large self-training models. They found the simpler features work okay without any real examples, but the big models perform much better when some real scam recordings are available. This shows a trade-off between quick deployment and accuracy in real situations.

What this means in practice

  • For call center security teams: Build lightweight voice phishing detectors usable immediately without needing real scam samples for training.
  • For voice ai developers: Develop accurate voice phishing classifiers leveraging few real scam recordings and self-supervised models for higher performance.

Authors

Jeongmin Lee, Seung Yun, Minkyu Lee, Ran Han, Yoonkyu Woo, Jinxia Huang

Abstract

Voice phishing detection faces three critical challenges: real criminal recordings are unavailable due to privacy constraints; when available, only a handful of samples exist, insufficient for fine-tuning; and lightweight acoustic-only detection is needed as an alternative to large self-supervised models. We compare domain-invariant prosodic features and self-supervised representations (HuBERT, wav2vec2.0) through cross-domain evaluation-training on scenario-based actor recordings and testing on authentic criminal calls. Domain-invariant prosodic features achieve 69.5% F1 zero-shot and 71.0% with 5-shot learning. HuBERT achieves highest performance (94.2% F1, 5-shot), while wav2vec2.0 exhibits a precision-oriented detection profile (90.2% F1 with 99.4% precision, 5-shot). These findings reveal fundamental trade-offs: domain-invariant features enable zero-shot deployment when no real data exists, while SSL methods achieve higher performance but require real samples and compute.