I have a sound meter and OEM fans tend to be 3-5 dB louder than aftermarket coolers.
Doing a lab test is not easy and I am not willing to spend the time or money to do a formal test.
So I offer what I can tell in an office environment.
This review on the AMD Wraith Prism gives a good indication of the amount of noise the CPU Cooler produces: [H]ardOCP: AMD Wraith Prism CPU Air Cooler Review .
This review on the AMD Wraith Max and Spire also gives good indications of amount of noise these CPU Coolers produces: AMD Wraith Max and Wraith Spire Coolers Benchmark Results | RelaxedTech
As a "Maximum"?
Well somewhat depends on your distance from them... but about 42dB (Stealth) / 48dB (Spire) / 55dB (Max) at 100%.
Yet as a key note, while this seems "Similar" to other Aftermarket Coolers., keep in mind that that:
a) they'll rarely actually be at 100%
b) the type of noise they produce is very different to most coolers., producing more of a Hum than a Whir
With an Optimised Fan Curve, as opposed to Default; for all intended purposes they're Near Silent at Idle., and will typically under Stock Clocks for their intended processors (i.e. what they're packaged with) Max out at ~40% RPM producing ~32dB (at most).
Which is noticeable, but again due to the type of noise it is... easily becomes background noise rather than noticeable.