in my opinion there is no way to get a dog to bark more on trail. ive tried for years and it did way more harm than good, but this is only one opinoin.some of the older dogs ive got have learned the quieter you are the closer you can get to the yote before he busts.i would go to http://nitro.20m.com/. its a site dedicated to yote hunters. go to their forum and ask the question. you will get more replys there than here.
good luck

Jeff S