Noise insulating wall structure

摘要

A noise insulating wall structure includes tubular extensions which extend into a space defined between spaced insulating plates. The extensions formed on the lower of the two plates are formed with openings which allow water, which accidentally finds its way into the interior of the panel, to drain out and thus not effect the sound attenuating performance of panel. The drain openings have an area which is determined based on a ratio of the area of the opening to the total circumferential area (including the area of the opening) of the extension.