of sound waves, asymptotes, and the reverse butterfly effect

I had always assumed that once something was said, the soundwave travels until it loses energy and eventually fades away but what if it doesn't? what if soundwaves behave more like asymptotes in that they lose energy and are always approaching zero but never quite reach it? what if this eternally decreasing soundwave reaches the other side of the world where it is gentle enough to help a butterly in it's flight? would it then be a reverse butterfly effect? just some questions to ponder.