<div class="section abstract"><div class="htmlview paragraph">Dash panel is the most important path of structure-borne and air-borne interior noise for engine-driven vehicles. Reinforcements, which are added to dash panel, are mainly designed in order to suppress the structure-borne noise contribution from the dash panel.</div><div class="htmlview paragraph">However, the effects of dash reinforcements do not seem clear in the viewpoint of air-borne noise. In this paper, the insulation performance of a dash structure with spot-welded reinforcements is studied through several STL (Sound Transmission Loss) tests and STL simulations.</div><div class="htmlview paragraph">The results of this study could be utilized for increasing the sound insulation performance of vehicle body structure.</div></div>