Non-native speakers often feel that the long a sounds like å, but native speakers don't agree. The thing is that we have more different vowel sounds in Swedish than you have in English, so it takes some time to get used to the unfamiliar sounds.
We're in an A/B test at the moment and I can only hear the new voice, which definitely gets it right.
To me, the first 'a' sounds different than the second 'a'. I mispelled my answer as "protar". I think I hear /prɔtɑr/ or at least /prɑːtar/. Maybe I have the old TTS voice. However, I am not hearing two different 'a' sounds with this alternate pronounciation with unknown dialect: http://forvo.com/word/pratar/#sv
The A/B test is over so everyone has the new voice. Of course the first, stressed, long a sounds very different from the second, short, unstressed one. I hear the first a as a clear long a, but it's a known phenomenon that learners often have trouble hearing the difference between that and the long å sound.
Stressed syllables can be long or short, but unstressed syllables are always short. There's no 100% rule for where stress falls, but usually on the first or second to last syllable in words that are not loan words. There are some links to pronouncing resources in the sticky thread under Discussions: https://www.duolingo.com/comment/5892805
Certainly, it is. It comes from the same thing, meaning to chat; it just didn't gain the connotation of endless unimportant chatter. The Swedish word pladder looks to be their prattle.
"Praktisk erfarenhet av Europa - inte mediernas pladder om Europa - är den pålitligaste och mest inspirerande källan till kunskap"