Is there some consensus/study on whether one should slow down music which one cannot play just by hearing it a couple of times (if the goal is to improve as a musician)? If I got a fast run, I can either slow it down and get it easily, or attempt to transcribe it at full speed, resulting in often listening to it dozens or hundreds of times.
On one hand, there's the idea that if something's making your brain hurt, you're probably doing the right thing, as stepping outside your comfort zone is going to make you improve the most.
On the other hand, there's the prevalent idea in ear training that students should be helped in every possible way - i.e. playing the interval over and over, slowly, not pressing the student to answer right away. This seems to suggest "going outside your comfort zone", at least on some level, is not a good idea for ear training.
So: slow down or go at full speed? (if the latter is even possible, which sometimes is not)