[ʊ] - near-close back rounded (short), [uː] - close back rounded (long). The other two are a bit more complicated to explain. There are two phonemes: /e/ and /e:/, which correspond to [ɛ] and [e:] respectively. [ɛ] - open-mid front unrounded (short), [e:] - close-mid front unrounded (long). [e] (short) is an allophone of /e/ but can be confused with [e:], which represents a different phoneme /e:/. In the spirit of teaching how it should be pronounced and being prescriptive for that reason, the word 'studet' should be pronounced ['stʊ.dɛt].
I've noticed that the audio is very weird for multiple reasons. For now, I'll chalk it up to a combination the course being in beta and the romans not having sound recording devices for us to use. However, if they come out of beta and it's still like this, then that's definitely not good.