Last time I was in the jungle bringing building material for a water project I encountered extreme noise. It came from this cricket (at least I think this is what it is) There must have been hundreds of them in the trees in one section of the forest making so much noise that my ears started hurting. Further down the path it stopped. So they were only in one part of the jungle.
Hier is a link to a post about a Zikada I found in the jungle. These are probably the biggest and noisiest insects I know.