At first I wasn't sure it was even there. The words tickled my ears and I couldn't make them out. I thought it might be the breath of a butterfly or the sneeze of a hummingbird. Then I picked out the occasional fragment of a word, maybe an -ee sound. Soon I was hearing a buzz more often, then much of the time, then always. Once I'd heard it properly, it was always the same, deep and forceful.