A system for real-time analysis of weld quality in an arc welding process. The system includes a transducer which receives acoustic signals generated during the welding process. The acoustic signals are then sampled and digitized. A signal processor calculates the root mean square and peak amplitudes of the digitized signals and transforms the digitized signal into a frequency domain signal. A data processor divides the frequency domain signal into a plurality of frequency bands and calculates the average power for each band. The average power values, in addition to the peak and root mean square amplitude values, are input to an artificial neural network for analysis of weld quality. Arc current and/or arc voltage signals may be input to the A/D converter alone or in combination with the acoustic signal data for subsequent signal processing and neural network analysis.