What the vagus nerve does
The vagus nerve is the tenth cranial nerve and the longest one. It runs from the brainstem through the neck to the heart, lungs and digestive system, carrying signals in both directions. It is the main nerve of the parasympathetic nervous system, the "rest and digest" branch that slows the heart after a scare, supports digestion and helps the body recover.
Its counterpart is the sympathetic nervous system, the "fight or flight" branch that speeds up the heart and breathing when we face stress. Both are always working; health depends on being able to move between them, not on switching one off.
What polyvagal theory says
Polyvagal theory was proposed by the psychiatrist and neuroscientist Stephen Porges in the 1990s. It describes three broad states of the nervous system: a "ventral vagal" state of safety and social connection, a sympathetic state of mobilization (fight or flight), and a "dorsal vagal" state of shutdown or collapse when a threat feels overwhelming. It also introduced the idea of "neuroception": the body detecting safety or danger before we are aware of it.
The theory became very popular in trauma therapy, coaching and wellness, because it gives people a simple language for experiences like feeling on edge, frozen or safe.
What the critics say
Many physiologists question the biological basis of polyvagal theory. A 2023 review by Paul Grossman argued that its core claims about how the vagus nerve evolved and how its branches work are not supported by the evidence. In short, the three states are a useful way of talking about how we feel, but they are not settled science about the nerve itself.
That does not make calming practices useless. It means that the benefits come from things we can actually measure, such as slower breathing, a calmer heart rate and a feeling of safety, and not from "resetting" a nerve.
| Safe and connected | Fight or flight | Shutdown | |
|---|---|---|---|
| Name in the theory | Ventral vagal | Sympathetic | Dorsal vagal |
| How it can feel | Calm, present, open to others | Restless, anxious, tense, irritable | Numb, exhausted, disconnected |
| Body signs | Steady breathing, relaxed face | Fast heart and breathing, tight muscles | Heaviness, low energy, slumped posture |
| What may help | Keep doing what supports it | Slow breathing, longer exhales, steady sound | Gentle movement, warmth, contact with others |
What does have evidence: slow breathing
Breathing slowly, around six breaths per minute, is one of the few things known to shift the body toward calm within minutes. A 2022 meta-analysis found that voluntary slow breathing increases heart rate variability, a common marker of parasympathetic (vagal) activity, during and right after practice. Longer exhales and a quiet, steady environment make it easier.
The exercise above offers two patterns: an even rhythm of 5 seconds in and 5 seconds out (six breaths per minute, the pace used in many studies) and the Sonovana rhythm we use in our video descriptions (inhale 4, hold 4, exhale 6, pause 2). Use whichever feels natural. If you feel light-headed, return to normal breathing.
How to use our nervous system soundscapes
- Lie down or sit with your back supported, lights low, phone face down.
- Start the video at a low volume and do the breathing exercise for the first 2 to 5 minutes.
- Then let your breath return to normal and simply listen. You do not need to do anything else.
- Use them at the same time each day, for example after work or before bed, so your body learns the routine.
- Notice how you feel before and after, instead of expecting a "reset".
A note on the word "reset"
Some of our video titles use expressions like "vagus nerve reset" because that is how many people search for this kind of sound. We use it as a figure of speech for slowing down. Sound does not stimulate the vagus nerve directly. Medical vagus nerve stimulation exists, but it uses devices prescribed by doctors for specific conditions such as epilepsy or depression, and it is something else entirely.
When to see a professional
If anxiety, panic attacks, trauma symptoms or exhaustion are affecting your daily life, talk to a doctor or a psychologist. Therapies such as cognitive behavioral therapy and trauma-focused treatments have strong evidence. See a doctor promptly for fainting, chest pain, palpitations or shortness of breath.