@AliciaWhiskers, I don't think you have to do it all in one sitting as you upload the recordings onto their software, but you can save them as you go on your computer and then upload them all onto their software. I did them all in one go, as the time consuming bit for me was thinking of the sentences!
The robot gets stuck on certain words and transcribes them wrong and I got round it by putting 'the' in front of the word. I think one of them was 'scene' and the robot.transcribed it as 'seem'. It's quite quick though once you get into it.