Q: Will acoustic panels stop the noise escaping from the room? Is it soundproofing?
A:
No, acoustic panels control reverberation (echo) and reflections within the room, but do not prevent sound escaping from a room.
In a normal house, sound is transmitted through the physical structure of the house to the outside environment, as well as through the air.
To soundproof a room to a very high level (such as totally stopping the sound of a drum kit) requires construction of a purpose built room that is "decoupled" from the surrounding environment.
That is, a room not physically linked to the surrounding environment by utilising an air gap, and by sitting the structure on rubber blocks. A room within a room.
