A dishwasher's decibel rating refers to how much noise the appliance makes when it is running, which can interfere with activities that take place nearby. Dishwashers that output fewer than 45 decibels are nearly silent, while 51 decibels or higher can make it difficult to hear a conversation.
For comparison, a vacuum cleaner runs at 70 decibels, a blender outputs 90 decibels and a motorcycle runs at 100 decibels. Dishwashers that include strainers rather than disposals, a common feature of European-made dishwashers, usually make less noise. Extra insulation and synthetic coatings also affect how quietly the appliances run. Dishwashers with lower decibel outputs usually command a higher price.