Haven't a clue about electric motors.

1. Ryobi table saw and B&D mains drill driven by carbon brush motors.
2. Washing and dishwasher machines driven by carbon brush motors, assuming that is a dishwasher has a carbon brush motor.

may sound a silly question but will settle an argument.

When using why are those in 1. noisier than those in 2.

bob, May 2015

Well I can't support your answer about rotating faster and being geared down and that causing the noise - what about his noisy Ryobi table saw? Rotates fast but no gearing down. What about a vacuum cleaner - no gearing there either - what about a jet engine? Not much rotation but lots of air.

No Toptrish - the noise is mostly down to the movement of the air - nothing to do with size or gearing.

The noise of the wind - just air movement - the noise from a nearby road or motorway - mostly air.

Windy Miller, May 2015

Drills and other portable motors have to be small for portability but small motors lack power so they are made to rotate a lot faster and are then geared down so they tend to be noisier,large appliances like washing machines are are a lot more powerful so do not need to go as fast and the gearing is by pulley belts so it is quieter

toptrish, May 2015

Carbon Brushes do not make any noise - a faint clicking at most.

The noise from rotating electrical machinery will be caused by some mechanical movement - rotating bearings etc - but most of the noise (90%) will be from the movement of air - an electric drill motor has an impeller to develop a cooling air flow - any reduced size motor will create excessive heat and will need forced air cooling - your vacuum cleaner for instance.

I do not believe that dishwashers have carbon brush motors - clothes washing machines do have brushes - they have more work to do.

You should also consider the wattage of the motor - more Watts will require more cooling and will make more air-noise.

This is a how to mend it site - it's not basic physics - electrical engineering for dummies or We Settle Your Bets.

You're fortunate that I feel sorry for you.

Personal research can be fun - try it., May 2015