Engine burp/growl between shifts
2010 WRX sedan, 1,635 miles. All stock.
This could be paranoia, but it seems like when I up- shift in the 3,000 - 4,000 rpm range I hear a burp or growl noise (like a more faint rev). The noise seems to be coming from the motor, and isn't as loud as the rev leading up to the shift. The noise happens while the clutch is in, as I'm up-shifting, not giving any throttle.
I'm thinking this is probably normal, because it's done it since I bought the car new. Just wanted to see if anyone else hears this sound and maybe what it's called.