Searching for in depth knowledge of audio

I’m trying to nail down the latency problems in AS3 Sound.play() method.
After collecting and calculating delays it seems that the latency basically always is a multiplier of approx 46 milliseconds, from 0 up to 185 (0, 46, 92, 139, 185) where 185 is in great majority.

What is it with this 46 millisecond value, can that be derived from some internal clock, sample rate or something else?