Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: Is this machine noisy at night?
Document: Buy yourself a hygrometer . Otherwise how will you know how much humidity is in the room. I recommend the one from Vicks for about 12 dollars. Dead simple. I found my bedroom at about 24 percent which was causing all kinds of sleeping problems. Using this humidifier I easily got it up to 44 percent and I slept like a rock. The machine is simple and not too noisy. Mine doesn't leak or anything. Great price for a simple machine.
Really pleased with this machine, it's very quiet, easy to use clean and works so well. I have used others but this one is worth it, has a good price to. Wouldn't use any other.
After our old humidifier stopped working, I went to another store (the word bed is part of the name) and purchased a Humidifier. It was very noisy. I took it back and then found this one online. It is quiet and works very very well.
That fixes it for a day or two, but then it starts acting up again.I think the problem is the calcium/mineral deposits in the water, which build up and somehow cause the machine to stop. Apparently, we have hard water. But so do a lot of people. I can understand the need to clean out deposits once a month, or maybe even once a week.
We bought this as additional humidifier for another room in the house. We got it because the first continues to work well. For some reason, this brand and model do not scale up as others we have had. And what scale is on the heating element comes off more easily than other brands we have owned in the past. The tank is big enough to run almost 24 hours on low, but is not so big that filling it and carrying it to the machine is a problem.
Takes me less than 30 seconds tops and I don't have to keep buying expensive distilled water. So many things are made to go obsolete it's nice to have something you can fix yourself. It's very quiet for a warm air humidifier, though it can gurgle a little when the water bubbles out the holding tank, but I like the noise it's just like a white noise machine.
It's picky - if you don't do the steps in the right order it won't turn on.Some times it doesn't turn on any way and I have to repeat. The blue light is almost impossible to see unless it's dark so many times I think it's on but it's not. I may have a bum unit but I think it has design flaws. I'm too lazy to send it back. It works and looks nice. It's just a touchy machine.
Thought the warm mist would be good, but there are several problems with this humidifier (1) noisy --although once I fell asleep, it was okay, and (2) i set the unit on a table and moisture must condense under the heating element and the combination ruined my table top. DO NOT BUY THIS ITEM.
the humidifier worked for a good year. it wasnt the best construction I have ever seen but it did its job without too much noise. once we removed the minerals etc, which it collects lots off, it never worked properly again. from not too noisy it went to a lot of different obnoxious sounds that never stopped again.also more water seems to be stagnant in the many lower compartments.overall not the best construction and quality!
I have only used evaporator type humidifiers in the past. They do a good job but are very noisy. This unit is silent by comparison. No filters appeals to me but this unit requires more cleaning to remove mineral deposits. I read other reviews before purchasing this unit and many had complained about this product leaking water. I have not had any problems with leaking at all. At first I used a drip pan under it and had saw no evidence of leakage.
Answer: It is very quiet.  It runs all night while we sleep.  Sometimes we have to go over to the machine and check to see if is still on. Even if you should happen to hear the unit, it is a "white noise" that will help you sleep.