[NKosmatos]

It never ceases to amaze me that light (the fastest and most powerful thing in our universe) can be easily blocked whereas sound, being less powerful and slower, is more penetrating. We can close the blinds/curtains and have total darkness, but try completely blocking the sound from the neighbors in such a simple way, impossible :-)

[saiya-jin]

All you need is a bit of hard vacuum in between, even micrometer thick layer is enough. Now how to do it continuously without joining parts is a bit of challenge now

[MadcapJake]

That is because light is a particle itself whereas sound is potential energy cascading through matter