This is a very common question and the solution depends on your room and your set up. Probably the best option is to create adouble wall with blankets around your drum set. and if you want the room to be available then use blankets with ceiling track kit. Even better if you double wall the blankets with an air gap between layers.(use 2 circles of ceiling tracks, about 4-6 inches apart). Hanging acoustic blankets on the ceiling track kit allows you to slide the blankets out of the way when you are not practicing your drums, so you can have the use of the whole room if you need to. It could also allow you to manage the sound inside the room (more live or more dead). If removing the blankets out if the way is not a p riority, you do not have to encircle the whole room with ceiling tracks. You can use ceiling screw hooks (available from your local hardware store) and only use tracks where you want to divide the room. This allows you to create a “room within a room” without building an actual “room”. For best results I would recommend covering walls with blankets entirely, even the walls you do not worry about. You want to eliminate that percussion sound bouncing off the walls. This will reduce overall sound pressure level inside the room and therefore even less sound will escape.