This is where phones and earbuds are so great. Some kids must have quiet in order to work, but other kids (especially ADHD kids) need the additional stimulation. i do better writing listening to music. But my subject, English, is a much more creative venture, so I'm not sure how this would work in say, math class. That being said, there are always kids who may lose their privilege by playing on their phones and not doing work, but I handle that on a student-by-student basis (ie, taking up a phone from a kid on it while I'm giving direct instruction to the class.