In order to give a score, your recording must be longer than one second. If it is less than one second, you will trigger an audio error. Normally this error happens when you click through the questions without answering. The best solution to this is to answer every question. Even if you can’t repeat the whole phrase back, try to do as much as you can. You will receive a better score.
This error can also occur if you have internet connectivity problems. To check your internet speed, visit this website: https://www.speedtest.net/.