A noisy dishwasher can disturb household conversations and interrupt leisure time. While some newer dishwasher models come with built-in soundproofing components, they may not eliminate all the noise. Older dishwasher models may not include any soundproofing components. You can easily insulate parts of the dishwasher and its surrounding environment to reduce the noise produced by the machine, regardless of whether the manufacturer labels it as a quiet unit.
Open the dishwasher and use a Phillip's-head screwdriver to remove the screws along the edge of the inside of the door. Close the door, and remove the front panel. Measure the length, width and depth of the front panel without the door.
Purchase a piece of sound-absorbent matting to match the depth of the front panel. Cut the matting with a utility knife to match the width and depth of the panel. Insert the matting into the panel, and replace the door. Open the dishwasher door and replace the screws to secure the door with the matting inside.
Pull the dishwasher away from the wall. Cut two strips of soundproof matting that are as tall as the washer, and 1 to 2 inches wide. Use a household adhesive to glue the strips to the vertical edges of the back of the dishwasher. Cut one piece of matting that is as wide as the dishwasher, and glue it to the top horizontal edge of the unit. Push the unit back against the wall. The matting will prevent knocking.
Measure the gap between the dishwasher and the dishwasher cabinet or counter. Cut a strip of wood molding with a hand saw to fit into the length of the gap. Cut a piece of the soundproof matting to match the dimensions of the wood strip, and glue it to the back of the strip. Push the strip between the counter and the dishwasher to block the noise. Do this only if the gap is larger than 1/2 inch.
Purchase dishwasher baskets for washing small dishes, lightweight cups or silverware. Dishwasher baskets hold these small pieces in place and prevent the jets from knocking them around, which can cause noise.