I own the Spurcycle bell. Funny thing, I noticed that older people did not react to it. Then I got a cold, and actually lost my high frequency hearing range. I would ring the bell and I could not hear it due to the hearing loss. When I would go to a piano, I found that I could not hear the top six keys as they were too high pitched. When I watched the video of the "oi" bell, I could hear the pitch clearly. I sent in the money to Knog, so I could get the bell as soon as possible.