On that note.. back when they used to end Television programs with a sign off of the national anthem. A unrelated subject but into the 60s they began changing the hertz in sound and frames per second in video. If you're curious or interested look into the national anthems subliminal messages. We consciously only see and hear at a certain level. An amazing book that illustrates this fact is ( the brain; the last frontier) sorry for the irrelevance on your topic.