Is the zoo surrounded on all 4 sides by main streets? The new elephant exhibit will definitely be subjected to a lot of noise from traffic so hopefully the high mud-banks will muffle some of the sounds from engines.
Not all four sides (there is a surrounding park that buffers the other sides). The elephant exhibit will have a small road leading into the park on the east side of the exhibit and a major street along the south side of the exhibit (just behind this wall). I had not really thought about the noise, but I am sure they will quickly get used to it. We are in the flight path for Davis-Monthan air force base and we have noisy fighter jets flying over all the time and the animals just seem to tune it out.