Contrast these exercises with Google's translate, where the speaker says every syllable of every word slowly and consistently each and every time.
But I feel audio at this point in my training is pointless and just gets in the way of learning vocabulary and grammar, which is what we should be focusing on. Audio comprehension is important but should only be introduced and taught after we have largely mastered grammar and have a lot of vocabulary under our belts, and it should start with distinguishing between tones.
As it stands now, I feel it's just wasting my time making, like trying to learn step 4 of something before you've completed steps 1-3. The speed of this speaker only makes it all worse.
Other Duolingo courses have a slowed down listening option. I am a bit deaf and find this useful when I have listened to the normal speed recording several times, but cannot understand part or all of what was said. I think it would be particularly helpful for the Vietnamese course. P.S. Pretty good English and basic French and Welsh; my Vietnamese is fairly dreadful and I live in Hoi An where there are quite a few pronunciation and vocab. differences from the Northern version that we are being taught