As the audio begins, the encompassing hum of a running water heater boiler fills the room. It is a steady, rhythmic hum, much like a heartbeat, providing a consistent background noise that is both soothing and calming. The sound of water running inside the boiler adds a sense of movement and life to the audio, creating a harmonious blend of mechanical and natural sounds. The room noise subtly implies that the boiler is located indoors, perhaps in a utility room or basement. The overall tone of the room, influenced by the humming of the boiler, is warm and comforting. The hum almost becomes a kind of room-tone, filling the space with its steady, undulating sound. Despite being a mechanical sound, there's something inherently peaceful and comforting about it.