I have volvo S70. Over small surface irregularities ther is a "PSS" like sound as if it is hydraulic. But when over lot of bumps the sound becomes more pronounced.I have changed all shock absorbers by new ones in volvo dealer. But the sound or noise is still there.
I appretiate any help for what cuold be the cause.

Thank´s

Were any other parts replaced at the same time?

no

Can you make the noise when sitting still pushing in the front of the car?

YES

Struts will make some noise when going up and down. Some are louder than other.
It is not a clunking or rubber moving noise is it?

On Bumpy road it sounds like "FLIH" continuously.

Sorry kind of hard to understand that. Is it kind of like a tapping?

I had a mechanic check the car and drove it. His conclusion is that the noise is from the shock absorbers. The onces that are installed by the dealer are SACH. Are these volo original parts? If so is it reasonable that they produce such noise. do I have the right to claim to the dealer or am I condemned to live with it?
I have another car with 200.000 km on and there is no absolute noise produced by the shock absorbers.

Thank you.

Most will have some.
I would say Yes on the OEM. Sach and Boge have become one company so you could have either name from OEM ones.

You could complain and see what they say.