Open-cell materials have improved acoustic performance over closed-cell materials. One promising way to optimize the acoustic performance of an open-cell material is to control its inner cellular-structural properties through the manipulation of processing parameters. This thesis work presents a novel method to process open-cell acoustic foams. A combined process of rotational foam molding and particulate leaching was used to process polymeric foams with desirable open-cell morphologies for acoustic absorption. Polypropylene (PP) and its nanocomposites were examined in this study. PP/MMT nanocomposites were synthesized with melt intercalation. An exothermic chemical blowing agent and salt particles were used to foam the polymer. Samples were characterized and tested for their cellular morphologies, acoustic and mechanical properties. Among the processing parameters examined, salt particle size is the major factor affecting the foams' acoustic properties. Correlations and conclusions from this study will be relevant to the development of new acoustic components with optimized acoustical efficiency.