Thanks for responding. The gutter drainpipe is at an angle along the side of the building and then it goes straight down but it is 3 feet above the ground. The water is going straight down into a recess in the ground that has some rocks in it and a deep pool of water develops and it is noisy. I have no idea why my super has installed the pipe the way he did but your suggestion makes a lot of sense. I will tell him and I hope he listens. He doesn't seem to want to change it and just wants to maybe put some foam rubber under it to silence it. I think the noise will also bother the tenant who will move in soon unless he or she can sleep through an earthquake. I am hoping that will soon motivate the super to fix it. He did install this Rain Gutter Accessory-Stop Noisy Downspouts
but it didn't help.