PNEUMATIC MASSAGE

A pneumatic system includes a passage to discharge compressed air and a sound attenuator including a first chamber in fluid communication with the passage and defined by a first wall through which the passage opens into the first chamber, a first surface of a second wall spaced from and opposite the first wall, and a sidewall extending between the first and second walls. The first chamber has a volume and includes a first opening in the sidewall. A second chamber is in fluid communication with the first opening and partially surrounds the first chamber. The second chamber is partially defined by a second surface of the second wall opposite the first surface and by the sidewall, and the second chamber has a volume and includes a second opening to exhaust air from the second chamber. The volume of the first chamber is less than that of the second chamber.