Andrew Huberman· PhD
So when you have a sound that's ongoing in the background, it shuts off, all of a sudden you experienced that peace, which is the turning off of those brainstem circuits that are associated with vigilance, the locus coeruleus, which we talked about earlier, which release epinephrin and norepinephrine and generate the heightened state of alertness in your brain and body, those neurons then can turn off and you experience that as relaxation.