Hi, just want to ask something
can i install in inside my wall? my wall was build by something like gypsum board inside like empty = =
those ppl taking at outside i can heard clearly in my room, it just too noisy
and those kid keep the shout.............
is like this

bedroom |_______| living room my wall i hide it inside
bedroom |__>____| living room
or must install it like bedroom |______|> <--- here?