Talking Books Production at the American Printing House for the Blind

Sorry but the narration reminds me of the film strips from school, kept waiting for the beep so I could turn the dial. That said, nice piece, informative and given the topic...you caught my interest....Nice job!!!! You made me interested in something  I never really thought about!!!!

Back in the 30s before they had editing software when they were first making these talking books, when the narrator made a mistake how did they correct them?