During sleep, you should create an appropriate atmosphere for the child. If this is a daytime sleep, then cut the curtains, but leave a minimum noise effect, such as: quietly working TV, conversations, noise of the street. But at night you should observe the silence. Before going to bed, limit the child in active games. They should be stopped in 2-3 hours. You can accustom him to the ritual before bedtime. For example, examining pictures, then bathing, after a lullaby or reading fairy tales.