I really think the comparison here is flawed. Speech is complex. IMO, much more complex than what PRIME does. Movement is largely an output. It's simple compared to speech. As is eyesight. It's an input. Speech is much more complex than a 'simple' input or output. And... Here's the really important part. Training. Every input or output that we've seen so far requires a significant amount of training. People with robotic prothesis need to learn how to use them. Take Cochlear implants for hearing: >Auditory Rehabilitation: This can last from several months to a year or more, depending on the user's needs and progress. It usually involves: >Weekly or bi-weekly sessions: Many users attend regular sessions with an audiologist or speech therapist. These sessions might be more frequent at the beginning (e.g., weekly) and can become less frequent (e.g., bi-weekly or monthly) as the user progresses. >Daily practice: Users are encouraged to practice listening exercises daily at home. This might include listening to recorded speech, using auditory training apps, or engaging in conversations with family members. I've followed several amputees who have prosthetic robotic limbs. It's a tremendous amount of work. When stutterers apply this amount of effort to their fluency, the results are typically very positive.