duolingo's pronuciation of "В"
When the computer voice reads sentences, I can't hear her/it pronouncing the word "B" (as in "Я в метро") when speaking at a normal pace, and when I play the slow audio, it is a very brief "f" sound. Is this indicative of the actual Russian pronunciation of this word, or a quirk of the computer voice?
This word is always used before another word, so the TTS does pronounce it unnaturally when making a pause after every word.
In speech, it sounds as "v" before a voiced consonant (or a vowel) and as "f" before a devoiced one.
Say va and fa very slowly and pay close attention to the position of your tongue as the air is being let out. How much difference is there?
Is it a big difference to a native's ear if we use the wrong sound of в in speech? When in doubt, is the "v" sound safer than "f" or vice versa?
Well, if you can pronounce vteatr and fdom...
Russian does not have a preposition that is pronounced ф, so, unnatural as it may sound, there is little possibility of misunderstanding if you do not implement the devoicing properly.