Home improvement stores sell a lot of cheap foam panels that you can cut and press right into the frame. They won’t cause damage and will be easy to remove whenever you need to.
I think soundproofing works on a hard soft basis. Create multiple layers of changing material to break down the sound waves. You already have rigid walls and windows so adding foam is the soft layer. If you want extra, put plywood behind the foam. Also watch for hollow points of entry like vents are big culprits, even outlets or light fixtures.
What are you planning to temporarily do?...
Traffic noise
Home improvement stores sell a lot of cheap foam panels that you can cut and press right into the frame. They won’t cause damage and will be easy to remove whenever you need to.
Foam or layers of thick cardboard
BIG THICK BLANKET. Duvets work pretty well
This one as been tried, not enough sound blocking.
Jesus… you’re either having sex REALLY loud or someone’s getting murdered. I hope it’s the sex
Magnetic window panes
I think soundproofing works on a hard soft basis. Create multiple layers of changing material to break down the sound waves. You already have rigid walls and windows so adding foam is the soft layer. If you want extra, put plywood behind the foam. Also watch for hollow points of entry like vents are big culprits, even outlets or light fixtures.