In this work we show preliminary results of the fabrication and acoustic characterization of air-actuable quasi 2D mechanical metamaterials. These metamaterials are based on an elastomeric matrix with cylindrical holes connected to each other by a cavity network of despicable size. By injecting or extracting air, these metamaterials change their mechanical response at low frequency in the audible range. As a result, a soft mechanical metamaterial is obtained, with tunability properties verified by acoustic characterization.