A ping is a sound wave and the layer interferes with it just as much as passive signals. However, once you get within a certain distance of a target (say 2 nmi or less, depends on the layer characteristics), the layer no longer works as the angle with which the sound hits the layer is too great to be reflected and it simply passes through.
I would also say the ping's bark is worse than its bite, so to speak. Unless they are really close, they're not going to detect you with pings too readily. It's like in
The Hunt for Red October movie, "hounds to the hunters".
Here are some results from my maximum ping range test (i.e., these are the best case maximum detection ranges you can get. Most scenarios reduce these already somewhat small numbers significantly):
Perry class OMNI active ping detection ranges against Kilo, Akula III, and Oscar II in RA 1.40 (ranges in nmi)
Perry class SINGLE BEAM/OMNI ROTATIONAL active ping detection ranges against Kilo, Akula III, and Oscar II in RA 1.40 (ranges in nmi)
