It's not bad during the day at all.
As for noise, if you're there at a weekend then there are a lot of people out and about and outside if the weather is nice.
We stayed in the Swiss'otel (good deal on Expedia) on Damrak and found it very quiet and central and we walked everywhere and did Anne Frank's house, Bols museum (opposite Van Gogh museum), canal tour, flower market, diamond museum, pancakes, fab zoo and all the major squares.
http://www.swissotel.com/EN/Destinations/Nethe rlands/Swissotel%20Amsterdam/Hotel%20Home/Hote l%20Home.htm
There is a good tram system though if you don't want to do much walking.
Breakfast is expensive there though so we would just go eat at a cafe on Damrak which was loads cheaper (about 5 euros a day).
There are loads of eating places down there and a little supermarket and it's very convenient for the train station if you are getting the train to and from the airport (soo much cheaper).