The method involves realizing a core (2), and associating finishing strips (8) on a portion of periphery of the core. Upper and lower coating material layers (5, 6) are respectively glued on upper and lower faces (3, 4) of the core, where the layers are ov...

The partition (4) has a rigid panel (20) with holes opening in each side of covering layers (22, 24) permeable to a sound wave. A film (26) that is impermeable to another sound wave having a frequency interval greater than that of the former sound wave is ...