Short answer is: Yes, it is! dont trust it too much.
The Long answer is: A lot of manufacturers out there like to boast about their decibel numbers like it’s the holy grail of dishwasher ratings. The truth is that the number is next to meaningless. As of right now there is no standardized industry wide test for determining how loud a dishwasher is. Each manufacturer leaves it up to themselves to construct a “test”, but there is no guideline to determine how far away a microphone is suppose to be away from the dishwasher, or how many microphones, or what are the settings on the microphone. Is it on an empty dishwasher or full? what kind of cycle? Is it average dB? or at the loudest point? Its completely up to the manufacturer to determine the testing. And they really like to play with the numbers to make their dishwasher seem like the best of the best.
Some manufacturers like to use sones measurement scale.sones rating on a dishwasher. eek
Some manufacturers go as far as suggesting that a sone is an accurate measurement of dishwasher noise level. Sone is basically a suggestive measurement of perception of noise. A subject is asked to rate a noise level on a scale of 1 to 10… give the same test to 100 people and then average the score and you come up with the sone value. So if you ever see a dishwasher with a rating of x sones… just laugh, the manufacturer is being very deceptive.
Don’t let the decibel rating fool you when buying a new dishwasher.
so to wrap it up, dB levels is really nothing more then another marketing scheme and it really should not be a determining factor in your dishwasher purchasing decision. There are a few manufacturers that do not post their decibel levels, such as Miele… and that’s not because they’re trying to hide something, its just that they dont like to play the little game.