How do I stop the banging?

I live above a pizza shop (decent apt, cheap rent) and usually it is pretty peaceful. However, they have a big hanging sign right outside my window that bangs the ledge outside my apt window when it is very windy. It happened twice and scared the heck out of me while sleeping. Is there anything I can do to fix the problem? or just deal with it? It is constant - just when it is very windy and the sign swings. TIAHow do I stop the banging?
Try using some of your special glue to hold that sign down
use gorilla glue to stick a rubber stop to the point that makes Impact, and attempt to tighten the areas the sign is hung from to cut down the play in the sign.How do I stop the banging?
Add a rubber buffer on the wall where the signboard hit it.The pizza shop owner should do it.

Fix the signboard to the wall with bolts at the lower portion.to prevent uplifting.
Ask the owners about how to fix it; since technically it's their sign.