Review on Syvio 2.8L Cool Mist Humidifier with Essential Oil Diffuser: Perfect for Bedroom, Large Room & Office, 24-Hour Top Fill Ultrasonic Air Humidifier with Whisper Quiet Operation, Auto Shut-Off & Night Light – Ideal for Home, Baby, Plants, Kids, Nursery; Easy to Clean by Stacy Jackson

Very quiet. It's quieter than my humidifier, which boiled water and used steam. This creates a sort of vortex in the water when the top cap and spout are removed, so anything that moves is underwater, making it very quiet in use. Noise level - water running water, like a small pet fountain, which has no motor sound. So it's very quiet, but what you hear is soft and maybe even sleep-friendly, depending on subjective tastes. This is the cool mist that comes out because no heat is used to create steam. As such, winter use will likely make the bedroom cooler, so adjust your heater vents to compensate. I liked my steamer for keeping my bedroom warm but it didn't even last 2 years so I'm hoping to get more out of it. So far I'd say it's definitely recommended at $38.99.