Promising review: “For anyone looking for a good balance between aesthetics and sound dampening, I believe these acoustic panels work really well! Don’t expect these panels alone to ‘completely sound proof’ a door. It’s only working so well because I sealed the side gaps with weather stripping, and the bottom gap with a draft blocker.

Panels are easily cut to size with an X-acto knife, and after hunting through some comments, were attached to the wall with Scotch-Mount Indoor Double-Sided tape. I divided the tape into 2x2in. squares and used about 3-4 squares per panel. Still holding on strong to the door almost a month later and looking great! Although accidentally, I found these panels stick pretty well to the stiff side of a Velcro strip. If you’re looking for a removable/repositional option, perhaps this could be the way to go?

Overall, they work great for reducing a good amount of sound that comes through the door. On the other side of the room where I sleep, a loud vacuum right outside the door is reduced to a whisper! Couldn’t recommend these (along with some weather stripping and a draft blocker) enough :)” —Josh F.

Get a 12-pack from Amazon for $24.99 (available in a variety of colors and either in non-adhesive or self-adhesive).

Source: https://www.buzzfeed.com/elizabethlilly/if-your-home-is-super-noisy-youll-appreciate-the