Tracking Grand Canyon Overflight Rules

Four microphones attached to tripods in remote areas of the Grand Canyon National Park are working for 50 days this summer to record the natural sounds of the park, in an effort to establish a baseline for “natural quiet.” The microphones record 10 seconds of sound every two minutes. That database, combined with another 50 days to be recorded this winter, will be analyzed by a computer to determine a “natural” decibel level, which can then be used to decide whether the current noise regulations that restrict overflights of the park are adequate. The goal is to have natural quiet in 50 percent of the park at least 75 percent of the time. Aircraft noise standards for the Grand Canyon have been under discussion for almost 20 years … and this summer’s data will no doubt add another layer to that discourse.