One of the biggest contributors to hood noise is the duct that goes from the hood to the outside. You could buy the quietest hood in the universe, but if the ductwork isn't sized correctly, it will be noisy. A hood with a typical 450-600 cfms usually requires a duct that is 8" in diameter. But many homes with exhaust ducts originally set up for microhoods have 6" or even 4" ducts. That means air will be forced through too small of a space, which creates noise.

In your new build, make sure your scope of work includes an 8" diameter hood exhaust duct. Don't let the builder contradict you and say that "a 6" diameter will be fine". A 6" diameter duct will be easier for him to install, but you have to live with it.

I've been talking about a hood with 450-600 cfms. If you plan on buying a large hood with 1000 cfms or more, your duct will need to be 10" diameter.

Other contributors to noise are if the exhaust duct going to the outside is very lengthy and/or has a lot of bends to it. If you are doing a new build, check into this early.

Also you need to be realistic that any motor, mounted at head height in your kitchen, is going to be noisy. So that is reality. If a very quiet exhaust is important, you can install a remote motor mounted at your roof instead, but that will be $$$.

Put the exhaust fan on the roof.

I have a roof mounted exhaust fan supplied by a 10" duct. There was no room for a silencer. No matter what you do if you are moving 1200-1400 cfm's you will hear it. As air is sucked thru the baffles it is going to make noise. Blow out air from your mouth hard and you will hear noise then multiply that by many times. I personally have never heard of a real quiet fan except for fantech and it was only for a bathroom and the fan was 20' away in an attic.