Expanded Clay Aggregate (ECA) has a highly porous and irregular surface. This means that is extremely effective at sound insulation. Sound waves that hit a concrete surface are reflected, which causes loud echoing. ECA, in contrast, absorbs the majority of sound waves. When added to plaster, or to concrete to create wall panels, ECA is extremely useful for sound or acoustic insulation and can help create acoustically-tuned rooms. And, due to its low cost and the ease of working with this material, it’s a perfect choice for large-scale building projects, including commercial lobbies and other such large spaces.