Ok, the end result I am looking for is a ringtone that can be heard by younger people, but not older people, the idea is from this site: http://www.textually.org/ringtonia/archives/2006/05/012473.htm It is a ringtone called "teen buzz" that is around the ~18kHz range, that only younger people can hear. I want this ringtone, but I can't find it anywhere. Does anyone know of either 1) know where i can find this ringtone, or 2) know how I can produce sounds in this range to make them into a ringtone(program, downloadable wav file...)? Thanks!