Why thoughts get louder

Why does it feel like my thoughts get louder the moment I sit?

In reality, the opposite is often true. When you sit for the first time, you are likely noticing the movement (thoughts, memories, planning, discomfort, restlessness) that was already present but you had never really paid attention to. Like the hum of a machine you have long since stopped hearing, it was simply below the threshold of your attention, until the stillness and quiet of the practice brought it to the surface.