Language / Google Translate - want know if the Polish pronunciations given are on an accurate level? [17]

Piję kawę

I have tried three translation engines Google, Bing and Ivona and I'm confused now :)

I have the Michel Thomas Polish CDs and the lady who is teaching is a native Polish speaker.
So she pronounces Piję kawę(I'm drinking coffee) more like Piyow Kavow (nasal sounding ow).

The translation engines pronounce the ę more like an 'a' sound.
Which is correct? If both are correct which one should I learn to use?

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