Most happy young chicks are quiet. If they are comfortable temp wise, fell fed, hydrated, and content they just make contented noises mostly. When I have a noisy chick I worry that something is not right. When they start to get older though they do get louder, they have to chat with each other and yell for treats, etc... It's like human babies, a newborn is much quieter than one that is a month old, and they just get louder as they get older. Not saying that tiny babies can't be very loud when they need to be! When your chicks are quiet think "happy baby" when they are loud think "crying baby."
My chicks for instance are nearly silent right now. All asleep with just the occasional quiet sleepy peep or trill. They are 1 and 2 weeks old respectively. Even when they are awake it's just quiet chatter amongst themselves.