How to notify contact events ? [SOLVED]

I can get sleep/wake events but I can’t get contact events and I need them to generate sounds accordingly …

So how can I get contact events please ?
Thanks

(Using PhysX 3)

I just can’t understand why such a basic thing is so complicated to get it works. I’m on user guide and API documentation for hours … for nothing :(

Sorry, I just omitted to put PxPairFlag::eNOTIFY_TOUCH_FOUND in the pair flags in the filter shader.