Stop Looking!
As far as I know - dishwashers and clothes washers do not need to have water pumped into them - a valve opens and the water flows in under the supply pressure - just like in the sink in your kitchen.
The rushing water will be making the noise you hear - you might try adjusting the stop valve for the house - or the circuit that feeds the machine - they usually have stop valves in the pipe near the connection point - you could turn that down a wee bit.
Noah
September 2014