it depends on so many things. hub shell thickness, spring tension, the ability of the tire/wheel combo to soak up any noise/vibration (try spinning the wheel with and without the tire on and you'll see). the main difference on a four pawl system is how much grease or lube is on the pawls. the drying the internals, the louder the noise, but the harder it is on your hub.
dt swiss hubs are odd, they have a very low number of engagement points, but are very strong. chris king have another different system which has a very high number of engagements with next to nothing for deadspots. ringle and most other hubs depend on how many pawls(springs/teeth) and engagement points on the inside of the hub shell for quickness of engaging.
Nothing wrong with a loud hub. I havea ringlé but only because its the only hub I know of thats 165mm, Its kinda loud, not too loud. I have heard some incredibly loud Hope pro IIs though.
i'd just also like to point out that my friend has a regular hope pro 2 and i have the trials version, mine has 48 points of engament and he has 22, and mine is not only more repetitive but its much louder.
you know how to make any hub loud? take the freehub off, wipe out all the grease and spray some wd-40 in there instead. put it back together, and now your hub is as loud as having some credit cards in your spokes.
just dont complain when the noise stops, and the bill for repair is $$$
if you are more interested in noise than performance, go get a ringle, because then your not wasting more money on a hub that feels better, but isnt as loud