Abstract: A water-proof sound apparatus comprising a sealed cabinet, filter means attached to said cabinet which is permeable to gases and impermeable to liquids, a speaker attached to said cabinet which has a water-proof construction, and a grill covering the front of said speaker. The above sound apparatus when used can be floated in water, and it can be washed with city water and the like. The relationship between the outside atmospheric pressure and the pressure in the cabinet can be adjusted in accordance with the changes in the atmospheric temperature, the atmospheric pressure, and the temperature in the cabinet, so that an excellent sound effect can be attained at all times.