Why is there running water sound in the pipes.
You probably have a leak somewhere if you hear water running and all the taps are shut off.
The reason is because the pipes are good conductors of sound and hence the resonance of the liquid is conveyed. In addition, it is not unusual to hear the sound of running water especially if the pipes are superficial.
did someone just flush the toilet? our pipes make that sound when we flush our toilet
Probably a leak somewhere....