Delayed Auditory Feedback in essence diverts your attentions into willings to achieve informations from what your conversation partners are saying and just manages to distract you from stutter. But hearing areas are indeed relevant to linguistic system which can potientially induce speech impediments like stutter, but DAF or Masker is not a hearing aid or something. You can assure whether your hearing is weak or not and you can figure out what I'm saying. Wearing something on your face is kinda weird and impolite and clearly, it's not the future of treatments. Since stutter is a neurological disorder, it is that the artificial repairments on brains will be the actual treatments.