Multi-source information of arc welding dynamic process.- Acoustic mechanism and arc sound source modeling for GTAW welding.- Feature extraction and analysis of arc sound signal with dynamic welding process.- Channel generation mechanism and modeling for arc sound signal during GTAW.- Prediction model establishment based on arc sound feature array.- Relationship modeling between weld pool collapse and welding penetration based on analyzing arc sound features.- Real-time control of welding penetration via arc sound signal for GTAW welding.- Microphone array technology in welding dynamic process monitoring.- Multi-source Information Fusion between Welding Arc Sound and other Welding dynamic processes.- Summary and Conclusions.