We can hear water going through a pipe constantly 24 hours a day. It is constant and is not affected by our taps being off. Our water supply is a shared supply from the mains to other properties apart from our own but even so it seems odd to have water on constantly and feel this must be a leak.  The fact that we can hear it inside our property and it is always running 24 hours a day and has been doing so for a long time is of concern as we don't know where it is going to.