The noise of running water
Finding a leak in a concrete floor through the noise of running water can be a difficult task. If you live in a noisy environment, this could be almost impossible.
But if you do hear the noise of water running during the night, and a thorough check of the house does not reveal any known cause, then the likelihood that there is a leaking pipe under the concrete floor cannot be ruled out. Take the necessary actions to verify there is a hidden leak. If you suspect one, it is wiser not to delay in calling for a professional slab leak detection.
A good plumbing company might offer a free inspection to verify other chances of leaks. Only when none are found will they offer estimates for a slab pipe inspection.