I actually had had an ear device that was purported to help with stutter. It "mimicked" what I had said, but in a higher pitch and audible only to me. The idea being that simultaneous speaking will solve my stutter. It actually did work to some extent, the only issue being that it picked up on every sound and noise around it aswell. So unless in optimal conditions, near complete silence, I wasn't able to hear that second voice. Anyway, knowing what I know now after all these years, it is a shortcut. It may be well meaning and might even improve in the future, but as the saying goes it's treating the symptom, not the disease.