We are often taught lectures in audio format. For most students there is no problem at all. But there are some who are hearing impaired. What to do?

I think the lecturer should think about this! And if for some reason this issue concerns the students themselves, I recommend trying to use transcribing. It is with its help that you can convert audio to text without any problems. If this option is interesting, go to the link https://any2text.com/ This is the best option to solve the problem.