Normal KitchenAid Dishwasher Operating Noises:
It is normal to hear some noise as the dishwasher runs through the cycle. Rushing, swishing water and humming are common noises that are normal to hear while the dishwasher is running.
Rushing Water Noise:
It is normal to hear a sound similar to water rushing while the dishwasher fills and cleans. The amount of sound is dependent on the installation. Dishwashers installed on the ends of cabinet rows may allow more sounds to be heard than ones installed between two cabinets.
Swishing Water Noise:
It is normal to hear a sound similar to water swishing as the water is sprayed on the dishes during the cycle.
See the following video for a better understanding of how the spray arms operate and cause some of these sounds:
It is normal to hear a humming noise during the operation of the dishwasher. This noise is heard when the dishwasher drain pump is running.