From the moment you turn ON, yes, you hear the motor working, but the blinds are closed and after a few seconds they open (don't expect it immediately) and it starts pulling. Furthermore, one blind stops for no reason, so it stays still while the delay never worked, it disappointed me a lot.
Advice: if the bathroom door is closed because the motor is strong, it will start pulling odors from the sink and bathtub drains after a while. The correct use is to leave the bathroom door slightly open to create pressure, and then the fan will pull everything out.