Thoreau writes in his journal:
Again I am advertised of the approach of a new season, as yesterday. The air is not only warmer and stiller, but has more of meaning or smothered voice to it, now that the hum of insects begins to be heard. You seem to have a great companion with you, are reassured by the scarcely audible hum, as if it were the noise of your own thinking. It is a voiceful and significant stillness . . .