In this particular example, I have the feeling to hear a very strong English “r” in the word “vire”. I guess that it depends on whether it's Portugal's or Brasil's Portuguese, but is that normal? I would expect to hear something more like a trilled “r”, like in Spanish, or even for Portugal a French “r”.
Thanks for your help!
I think it should be pronounced like example 4 here:
To check, listen to the word spoken by Brazilians: http://www.forvo.com/word/vire/#pt
Thanks a lot! I'm a little surprise to hear these sounds (I was expecting more… latin sounds, maybe?), but this helps a lot! ☺ This is something that Duolingo (to my opinion) does not sufficiently insist on: where comes the accent we are hearing ;-) I have the feeling that the voice is not far from São Pãulo, but I may be wrong!
The "r" in this case is like the "tt" in "little", in American English (a flap of the tip of your tongue, technically an alveolar flap). You can't go wrong if you start from there.
But be aware that both the initial "r" and the double "rr" have a different sound, more like "h" in (hot), but voiced. That is, besides the aspiration, your throat, has to vibrate. Try to say "ssss" and "zzzz" to notice the vibration of the consonant in the latter, but not in the former. Then try to vibrate your throat when saying the "h" in "hot" like you did with "zzzz" (but now without your tongue, of course).
caro (expensive) => "r" sounds like "tt" in "cattle"
carro (car), rato (mouse) => "r" sounds like the "h" in "hot", but voiced
carta (letter) => like the "h" in "hot", but voiced
Individual accent may count. I met people in São Paulo who always use the "tt" version for any occurrence of "r".
Also in some parts of São Paulo people tend to pronounce the "r" before a consonant (or the final "r") kind of like the "r" in English in "bar".
And in some parts of Minas Gerais, the "r" before a consonant tends to be softer than usual, resembling "h" in "hot" more closely (not voiced).
But all these variations are mutually intelligible.
To me, the sound you're describing as a "voiced h" is very similar to the way R is pronounced in French, with the back of the tongue in the throat rather than the tip on the roof of the mouth. The difference is that the French tend to roll their Rs a bit longer, and the Portuguese RR (and initial R) are quick.