Is it sensible for the expert to inspect the base plate?

Only for the washbasin, only the washbasin towards the children's room, does it make a lot of noise? It was actually all like that earlier....

I have now tested. When I turn on the water at the washbasin in the bathroom, I only hear the rushing of the main water pipe in the utility room adjacent to it, nothing from the washbasin.

In the past, however, you also had solid brick walls. The interior walls should have as much air as the exterior walls, but depending on the thickness, you can hear it more or less. Whether washbasins too, I don't know. For me, it's just the bathtub.