I'm not an expert but I would think understanding would depend on the room acoustics, class size, and the professor teaching and his techniques.
But for the recording part, unless you get a special pass or accommodation, is completely up to the professor. I've had ones who had no problem and those that would ban you from class.
I would ask to college and the professors themselves as well and depending on circumstances asking for what you need for accommodations .
I can stick with smaller class and no to little accommodation but my cousin Angie needs an fm system or note taker for any class.
No matter hearing status, when it comes to college it is always a good idea to go early, ask lots of questions, and get to know your professors.