My roca toilet makes a pressure wooshing noise?

you can be sat down stairs and you can here this wooshing noise sounds like pressure from the toilets but cant figure out why its doing it..............can anyone give me any help???|||I assume you mean when it is re-filling after flushing. it could be that the inlet is restricted in some way. Check that the shut-off valve is fully open. If this it not it then may be there is some debris in the pipe near the ball valve .|||Its normal Its the best sound in the world it makes me hard