Make your own sound wave necklace from an audio clip with tutorial at Instructables. Your sound can be anything from a line in song or you telling your significant other you love them. :)
DIY will require downloading some software and working with a laser cutting printer (he suggests Ponoko). Or you can have one made by the artist David Bizer himself.
P.S. I think it’s awesome that he offers a tutorial for anyone who wants one of these but can’t afford his prices.