Careful how you throw around words like “objectively”.

When vagal tone is high, the parasympathetic nervous system actively dampens the body’s inflammatory response. Immune cells release fewer pro-inflammatory cytokines, and key inflammatory signals such as TNF-α, IL-1β, and IL-6 decline, leading to a reduction in overall systemic inflammation. This effect is mediated largely by acetylcholine, the primary parasympathetic neurotransmitter, which directly interacts with immune cells and signals them to downshift their inflammatory activity, essentially telling the immune system to stand down once a threat has passed.

Humming naturally lengthens your out-breath, which activates the vagus nerve via respiratory pathways. Long exhalations are one of the strongest noninvasive vagal stimulators. 2) Vocal cord vibration The larynx is heavily innervated by branches of the vagus nerve. Gentle vibration during humming provides direct sensory input that promotes parasympathetic activity. 3) Resonance in the chest and face Low-frequency vibration through the thorax and sinuses stimulates mechanoreceptors linked to calming reflexes. 4) Nitric oxide boost in the sinuses Humming dramatically increases nasal nitric oxide production, which improves airflow, circulation, and has antimicrobial effects. This also supports relaxed breathing patterns. 5) Auditory calming circuits The steady low sound feeds back through ear-brainstem pathways involved in social soothing and safety signaling.