Because the Irish course on Duolingo doesn't use a computerized Text to Speech system, any audio has to be pre-recorded, and you won't get audio for every sentence.
A similar sentence, Itheann sí ceapaire sicín does have audio, and if you search for both itheann and sicín in the Irish discussions, you'll find other recordings.
I have no idea what "fusional" means, but Irish, like English, has separate forms for the simple present ("itheann tú sicín"/"you eat chicken") and the present progressive ("tá tú ag ithe sicín"/"you are eating chicken"). These are quite distinct forms, and you can't translate from the Irish simple present to the English present progressive, because they don't mean the same thing.
That makes a lot more sense. As for the term "fusional," here's a good explanation: http://www.glossary.sil.org/term/fusional-language