Voice onset time is the timing difference between the release of a sound and starting to make the vocal folds vibrate. Voice onset time thus explains the difference between aspirated and unaspirated consonants. If the voice onset time is very small, then the consonant is perceived as unaspirated, while if the VOT is large enough, he consonant will be an aspirated one. The same holds for voiced consonants.
Turbulence causes some vibration of course, though a very high frequency one.
I hope that this doesn't sound too much like gibberish.