Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Incredibly loud rattling noise.

Really unhappy with my purchase. Returned it immediately. De-boxed it and plugged it in. It made huge clanking noises. I tried adjusting the flow of the air, but nothing worked and it was so much louder than the sound of my fan. I am an extremely light sleeper and even the sound variation from my fan keeps me up at night. I read all the good reviews and the bad reviews and thought that it wouldn't hurt to try it since so many people seemed to like this product. I was really pretty much praying that this would be the answer to my sleeping problems, but it wasn't.