Give a summary of "The Sound Machine."

The protagonist of "The Sound Machine" is a rather eccentric man by the name of Klausner. He has an obsession with sound, and he is absolutely convinced that there are many sounds in the world that humans are unable to hear due to their high frequencies. In order to be able to hear them, Klausner invents a machine that he hopes will turn the high frequencies into audible sounds.
The first time he tries out his strange new invention, Klausner hears what appears to be a shrieking sound as his neighbor cuts roses in her garden. Every time a flower is cut he hears the same sound through his headphones. Klausner is convinced that the flowers are talking to him, expressing their suffering and pain.
The next day he tries a more ambitious experiment. He takes an ax and sinks it into a beech tree. Once again, Klausner hears a sound; this time it's a deep, sad moan. Klausner thinks he's going out of his mind, so he summons his doctor. He wants the doctor to hear the sound for himself just so he knows that he isn't hearing things. The doctor comes over and listens in on the headphones while Klausner gets ready to take another big swing at the tree. But before he can do so, a branch falls from the tree, destroying Klausner's sound machine. The doctor claims not to have heard any sounds, but accedes to Klausner's unusual request to dress the beech tree's cuts with iodine.