With regard to recent shipbuilding techniques, welding technicians with advanced skills in fabricating steel structures is decreasing. In particular, there is concern about a decrease in productivity and weld quality in the field where welding is used for various applications. The author has been working in cooperation with Nagasaki Prefecture since 2013 to develop a "shipbuilding technology simulator" to educate unskilled young technicians at the production site of the shipbuilding industry. He developed a simulator utilizing the ICT and performs the assessment of technicians welding skills and the visualization of technical knowledge. In this study, for the purpose of development of welding simulator, it was decided to investigate out a study on the determination of weld quality by the operator using the welding arc sound.