I am doing my NPPl at Denham and was a bit concerned that there might be an issue - obviously dont want to spend loads of money only to find out I can not pass the RT
Don't worry about it - at the moment, it's meaningless gobbledegook. Once you know what you are listening out for, it all begins to make sense. Your ears become tuned to it!
If ever you are having any difficulty understanding someone, you can always just say 'Say Again'