Do you know from which episode of the Twilight Zone the sounds of kids are coming from ?
they're coming from "Kick the Can"
this is the synopsis :
Charles Whitley, a retiree at the Sunnyvale Rest Home, thinks that he has discovered the secret of youth. He is convinced that if he acts young he will become young. His oldest and best friend, Ben Conroy, thinks he is going crazy. One night, Charles convinces a number of residents to play a game of kick the can with him. When he tries to talk to Ben, Ben tells Charles, "I AM old!"
The game of kick the can transforms Whitley and his other friends back into children. Conroy and the home's superintendent, Mr. Cox, go out to the street where they find the group of children playing kick the can in the night. Mr. Cox chases them all off except for one, who stops to look at Conroy. Ben, now seeing the miracle, begs for a second chance to go with his friend. But it is too late: He is left behind.