The Voo Breath: Vagal Activation Through Sound

Slow exhalation, chest resonance, and vagal activation — the mechanism and the evidence

What is the Voo breath, and does making a "Voo" sound actually calm the nervous system?

The Voo breath is a practice from Peter Levine’s Somatic Experiencing in which you exhale slowly while voicing a low, resonant "Voo" sound — think foghorn, felt in the chest and belly. The extended exhalation and the resonant vibration both stimulate the vagus nerve, shifting the autonomic balance toward the parasympathetic "rest and digest" state. The vagal mechanism is physiologically plausible and consistent with broader evidence on humming, chanting, and slow-exhale breathing; this specific practice has not been tested in independent controlled trials.

Peter Levine developed Somatic Experiencing around the idea that the nervous system can get "stuck" after overwhelming experience, and that simple, body-based practices can help it complete the regulation cycle and settle. The Voo breath is one of his signature exercises: a long, hummed exhalation that he describes as activating the vagus nerve through vibration and extended breath. The practice takes under a minute, requires nothing but your voice, and is low-risk for almost everyone. The mechanistic rationale is solid; clinical trial evidence is absent. Use it as a nervous-system tool, not a medical treatment.