Trying to see if this is normal or if anyone has this same "issue"

When I turn on my car and put in reverse the turbo flutters and when I put in drive it flutters again. Once I start driving i hear no flutter what so ever. Anyone have this issue or should I be worried? Car is still under warranty, so if it is something major i am sure it would be covered, but when I went to Audi, they said it was normal for the car to make "weird noises"