Quite within limits. If you turn down the fan speed in Bios, it still cools very well.

I find both the question and the answer very funny, because you can google it in less than 2 minutes.
The answer to your question:
The Corsair iCUE Link H115i has a noise level between 10 and 36 dBA. The fans rotate between 400 and 2400 revolutions per minute. In minimum operation, they are barely perceptible to the user, partly due to the pump.
If you are now wondering how loud 36 dBA is: These levels are not particularly loud for the human ear. They correspond to noises such as whispering, rustling leaves or background noises in the house.