Unfortunately, there is no other way to deal with this, because if you get the same exercise in a written form, the alternative answer will still apply, but that would be wrong.
We need to re-disable all similar exercises, because the course recently upgraded its voices, so the old settings were rolled back.
Actually what just came to my mind is that right now it doesn't matter much because the users don't get the 'you made a typo' message when doing listening exercises. It's a known bug.
But when the bug is fixed, well, it's kinda unfair that one could get 'accused' of making a typo despite actually writing exactly what was said. So that's why we disable those exercises, hoping that in some time we'll just get the chance to add homophones and both answers will be considered equally correct - but only in the listening exercises.