How is noise made by armor determined? Is it based on weight of the armor or something else, and if so does taking perks that remove any weight from equipped armor affect affect the noise?
I remember that you could sneak in heavy armor in previous games if you took off the boots, but I don't know how it works now.

NEVERMIND

According to the perks that you can find, there's a sneak perk that reduces the sound of all armour by 50%

Now I assume that the more and the heavier the armour is regardless of other perks, the more sound you make. So a person who sneaks around in full heavy armour will make more sound than a person running around in lets say robes.

This. Hopefully the sound effect is weighted heavily. Thus making light armor geared towards stealth.