"Ten pes vidí kočky."

Translation: The dog sees the cats.

[Tielbert]

This dog sees cats - why marked wrong?

[endless_sleeper]

Tento/Tenhle pes ^

[Denial.911]

pes - dog as main noun in the sentence
ko^cky - cats as direct object

is that correct?

[VladaFu]

yes

[Kiki685123]

Why is it 'the cats' and not just 'cats'

[VladaFu]

Both are possible. There are no articles in Czech. It depends on the specific situation whether there are any specific the cats to talk about.

[FriedrichS165206]

accustic level is poor. the spoken speach could be understand only by accident

[VladaFu]

Place your generic comments about the new voice to the appropriate place https://forum.duolingo.com/comment/37772239

The stress of the new voice in this sentence is not the best, and is worse than the older voice, but you will surely find worse in the real life. And people still have to understand those.