Sylia does that too. But it's a running spring's sound (I have water dispenser). She does that sound every time I make coffee or tea, or simply fill a glass of water. But when I give the water to her she ALWAYS ask ''Is it fresh?'', I answer ''Yes, it's fresh!'', and she always ask again '' Fresh fresh??''. It's very cute, I think. My hubby sometimes comments ''What? She do not trust us to give her clean water?'' Of course he is joking