It Started Getting Louder
There are many other weird sounds a house makes and perfectly good reasons why it’s making them. From clicks and bangs to bubbling sounds, most are temperature-related, such as the thermostat, water heater, and even just heat drawing out of the house at night.
So obviously when the noise started, it was explained away as regular noises because the house had not been used for a long time. What became strange about the sound was that it wasn’t only happening at night, and its volume was changing. This got the family worried.