Picture shows - The recordings are saved to wax cylinders as shown, and are filed for a short period before being 'shaved' and used again. BBC Monitoring would use wax cylinders which could be shaved and re-used. Sometimes the shaving was incomplete and the monitor could hear remnants of the previous recording, which could be confusing, especially if it was in the same language.
Your download will start shortly, please do not navigate away from this page until the download prompt has appeared. Doing so may cause your download to be interrupted.