On Twitter, a short black and white video documents the work of sound effects in the studios of Walt Disney in 1941. In this millimeter sequence, the sound effects perform live the sound design of the unfortunate Casey Junior, the anthropomorphic steam engine of the Dragon recalcitrant. Cello out of tune, scrap metal of all kinds, coffee pots, screeching of glass and landslides punctuate the passage of the train. The sound of her whistle is produced thanks to a vocoder which captures the vibrations of the throat, thanks to sensors placed on the neck of the dubbing actress. We let the images speak for us.