I Agree with Jean though. My birds are housed in my bedroom and I do have a little 13 inch TV in there close to my bed, but it's not always on. The 2 Tiels I have seem to sleep fine when covered with the blanket. Charlie will be singing up a storm, and within like 90 seconds of covering the cage, he stops completely. It works for me, anyway. I don't see myself buying a sleep cage anytime in the future.