Does "leaf-shushed world" means a peaceful world like when you are in the woods, and all you hear is the sound of fallen leaves under your feet when you step on them?
Freddy wants a tree-house, and I always meant to build one in the copper beech. Nothing fancy – just a sort of tree-borne raft, like the one me and David Ockeridge built in his dad's orchard, when we were kids in Black Swan Green. In my daydream I'd tell Fred that the copper beech is guarding his prezzie, and I'd watch him run down, find the rope ladder, and climb up to a better, leaf-shushed world. The thought of another man building Freddy's tree-house in an ordinary green beech made me hurl my trowel through the shed window. Shark-fins of crashing glass followed the trowel.
Excerpt from David Mitchell's The Massive Rat.