for the first time since his embarkation , being effectively detached from the hurly burly of normal deck life by his shipmates imposed regime of isolation , martin was suddenly aware of the sights , sounds and smells of the natural world through which he was slowly passing : there were monkeys chattering in the high branches of the trees and a steady background hum of insect noise , vibrant like an amplified , electronic instrument , constant like a geiger meter registering the count for background radiation .