As a hard and software engineer I like to develop my own applications to control my trains. I was playing around with the old Roco NextGen locomotives and developed a throttle control for it because these locomotives just use the z21 protocol. One thing i missed at the end was sound. So i dived into the ESU lokprogrammer software to see if I could use there sounds files. This was quite easy to use and i now have a throttle control with ESU sound support. The application also supports the z21 protocol so you can attach sound to a loco with a standard decoder.