An acoustic panel for reducing the transmission of noise therethrough is provided. The acoustic panel may include a sound-absorbing surface with a plurality of convex and concave structures. The convex and concave structures may be organized in a regular array and may be spatially arranged to be alternating with one another. A dishwasher may use such an acoustic panel including a panel of sound absorbing material by placing such a panel inside the door, in or around the walls of the tub of a dishwasher, or the panel can also be used to reduce the transmission of noise with other products. A method of inserting a panel of sound-absorbing material into the door of a dishwasher is also provided. The panel may include protrusions extending from one of its surfaces in order to engage a supporting surface of the product to which it is attached.