How do I block any kind of light of a window? Imagine a situation where a really strong 9000 Lumen flashlight is directly pointed to that window. There can't be any sign of light in the room. Some kind of blackout sheeting right on the window glass? Blackout curtains that get attached directly on the window frame?

 

Furthermore: Is there a better way than buying pic 2 relatedish to defend against projectiles hitting the window (projectile from a slingshot probably). I don't think actually damaging or destroying the window is the goal, it's about the noise the hit creates.

How could I dampen the sound of the hit? Thick blackout curtains do dampen sound I think, but is it enough?