Correct me if I am wrong but I dont think anyone reading this can likely hear anything above 20khz, and most can only hear to around 16 khz. Check this out for what it is worth. Hearing Test - Can you hear it?

Okay been lurking for a couple of weeks @ Head-Fi but when I saw the rubber band-fi thread I had to register... The best rubber bands are bicycle tire tubes cut to width yourself. They are strong, and can be cut to to whatever width you desire and they look Macho. Cut a bunch and then wash...