I had a speech therapist make me do this when I was 12 or 13 and not only did it not seem to help but I fucking hated doing it. I think my therapist wanted me to do 15 minutes a couple times a week but my parents thought if a little was good a lot was better so they had me reading into a tape recorder for 30 minutes every day. Went like that for a few months until I got fed up with it and got in a screaming match with my step-dad. I'm still not sure what the bloody point was; I don't stutter much when I talk to myself and listening back to it was an exercise in learning to hate how I sound on tape. 2/10, would not recommend. Your mileage may vary.