Vagus Nerve Activation by Humming or Gargling

Try it at the sink (about 3 minutes)

This three-round comparison shows you what the studies below were trying to separate:

1. Silent exhale (1 minute). Sit upright. Breathe in through your nose and out through your nose, slowly and quietly, with a long, easy exhale.

2. Hum (1 minute). Repeat the same breathing, but close your lips and hum a low, soft "mm" for the whole exhale. Feel for the buzz in your lips, jaw and chest.

3. Gargle (30 seconds, optional). Take one small mouthful of water, tilt your chin up only slightly, gargle a gentle low note for a few seconds and spit. Skip this round if you have trouble swallowing or tend to cough on liquids.

Then ask which round was easiest to keep going and whether the hum changed how your jaw, throat or shoulders felt compared with the silent round. The rounds are practical suggestions and not a tested protocol.

Where does the vagus nerve reach the throat?

The vagus runs from the brainstem down through the neck to the chest and abdomen, and it is dominated by sensory axons [2]. In the throat, two branches, the superior laryngeal nerve and the recurrent laryngeal nerve, supply the pharynx, epiglottis, larynx and vocal folds. They set off protective reflexes such as swallowing, vocal fold closure and coughing [1].

That anatomy is the case for both practices. A hum vibrates the larynx and gargling moves water against the back of the throat, so the nerve endings there have something to detect. The step from "something to detect" to "the nerve is activated in a way that changes the body" is a hypothesis. The studies below tracked heart rhythm and breathing, which are indirect signs of how the nerve is doing.

What happened when people hummed?

In a crossover trial of 118 people at a wellness center, each person hummed with breath lengths of 8, 10, 12 and 14 seconds in random order. Heart rate variability (HRV) peaked at breath lengths of 12 to 14 seconds, longer than the 10 seconds that biofeedback breathing studies had found [3]. The sample was a convenience sample and the study measured HRV during the practice, so it points to a comfortable range for the exhale and says nothing about lasting effects. A hum that lasts as long as your exhale does is enough to begin with.

A smaller study followed 16 healthy volunteers through humming breath practice. During the practice, heart rate and low-frequency HRV rose and high-frequency HRV fell, a pattern the authors read as possible parasympathetic withdrawal during the practice, and the values reverted afterward [4]. Together, the two studies show that humming changes heart rhythm in measurable ways. They differ on what happens during practice, and in the smaller study the changes did not persist afterward, so how long any effect lasts is still unmeasured.

Is it the hum or the slow exhale?

Singing studies come closest to answering this. Three are worth knowing:

• Paced breathing versus paced singing (four groups). Both raised low-frequency HRV at 0.1 Hz, a rhythm of one cycle every 10 seconds. The singing groups also had higher heart rate and blood pressure and more positive affect, and neither approach had a robust effect on cardiovascular stress reactivity [5].

• Vocalizing versus matched breathing (2026). Participants with no musical training toned (sounded a vocal tone for the length of the exhale), sang slow familiar songs, or breathed at the same rates without sound. The overall HRV measure (SDNN) rose during toning and during matched slow breathing. RMSSD, the index the authors used for vagal tone, rose with slow breathing but not with vocalizing. Alpha and theta brain activity rose at rest after toning and singing but not after matched breathing [6].

• Humming versus singing (healthy 18-year-olds). Participants hummed a single tone with free breathing, sang a hymn, and sang a slow mantra with breaths only between phrases. The study reported that song structure, respiration and heart rate are connected, and that unison singing of regular song structures made singers' hearts speed up and slow down together [7].

Taken together, these studies point to the long exhale as the part doing most of the work, and humming is a convenient way to produce it. Where the breathing was matched, the HRV effects were similar with or without sound, so the vibration itself has not been shown to add to them. The brain-rhythm result suggests voice may add something of its own, while the heart-based marker of vagal tone favored plain slow breathing.

If you enjoy humming, it is a pleasant way to hold a long exhale. If you prefer a voice to set the pace, the mindfulness apps with breathing exercises compared on Pulsetto's blog do the same job without any noise.

What about gargling?

Gargling works the throat muscles and reflexes the vagus helps run, which is the reasoning behind using it for the vagus nerve. It asks for the same slow, steady control as humming, which makes it a reasonable practice to try.

Gargling carries one real risk that humming does not. The throat reflexes that guard the airway can fail, and when they do the result can be choking and aspiration pneumonia [1]. Use small mouthfuls, keep your chin level or tilted only a little, and stop if you cough. Anyone with swallowing difficulty or a throat or neck condition should skip it.

How to use humming and gargling

Here is the routine in one place, using the practices from the studies above. Pick one row, or run the comparison in the last row to find which suits you:

Where Pulsetto fits

Humming needs a quiet moment and gargling needs a sink. If you want something you can use at a desk or on a train, Pulsetto is a vagus nerve stimulator that sits on the neck with electrode gel and runs short programs from a free app, including a 4-minute Stress program. 

In Pulsetto's own randomized, open-label pilot study (n=40, 4 weeks), hair cortisol, a longer-term stress marker, was lower in 70.3% of participants, with a mean reduction of 47.5% among those whose levels fell (bilateral stimulation). 

Disclaimer: Pulsetto is a general wellness product and is not a medical device. Do not use it if you have a pacemaker or an implantable medical device, or if you have epilepsy. Do not use it while pregnant unless a healthcare provider has cleared you. Talk to a doctor first if you have a cardiovascular condition or carotid artery problems, or if you have had recent neck or throat surgery or injury.

Try the sink test before your next meeting

Run the three rounds once, note which one you could have kept going longest, and use that one as your reset. If you want a device option for the moments when you cannot hum, Pulsetto is there for that.

Vagus Nerve Activation by Humming or Gargling FAQs

Is gargling safe to try?

For most healthy adults, a few seconds with a small mouthful of water is low risk. The concern is the airway: if the protective reflexes in the throat fail, water can be breathed in [1]. Keep the mouthfuls small and spit the water out. Skip gargling if you have trouble swallowing.

Can gargling help you avoid colds?

One randomized trial of 387 healthy volunteers found that people who gargled water at least three times a day for 60 days had fewer upper respiratory tract infections than those given no instruction (incidence rate ratio 0.64, 95% CI 0.41 to 0.99) [8]. A later trial in 600 students did not find a significant reduction in clinical infections in its gargling group [9]. Both trials tested infection rates and neither measured the vagus nerve, so the evidence supports gargling water for the throat and says nothing yet about the nerve.

Does humming do anything for your sinuses?

Humming raised nasal nitric oxide about 15-fold compared with quiet exhalation in 10 healthy volunteers, and the authors proposed that the vibration improves ventilation of the sinuses [10]. A later study tested whether that nitric oxide boost helped short-term thinking or emotional processing and found no improvement [11]. The sinus effect is measured and small in scale, and it is a separate question from the vagus nerve.

Who should not use Pulsetto?

Do not use Pulsetto if you have a pacemaker, an implantable medical device, or epilepsy, and do not use it while pregnant unless a healthcare provider has cleared you. Talk to a doctor first if you have a cardiovascular condition, recent neck or throat surgery or injury, or carotid artery problems.

Scientific research

1. Commentary: Vagal P2RY1 Receptors: A Novel Target for Airway Disease (Liu et al., 2020, Frontiers in Pharmacology)

2. Structure and Functions of the Vagus Nerve in Mammals (Ottaviani et al., 2022, Comprehensive Physiology)

3. Effect of Various Lengths of Respiration on Heart Rate Variability during Simple Bhramari (Humming) (Trivedi et al., 2023, International Journal of Yoga)

4. Heart Rate Variability Changes During and after the Practice of Bhramari Pranayama (Nivethitha et al., 2017, International Journal of Yoga)

5. Singing at 0.1 Hz as a Resonance Frequency Intervention to Reduce Cardiovascular Stress Reactivity? (Tanzmeister et al., 2022, Frontiers in Psychiatry)

6. Neural and cardiorespiratory responses in vocalization and slow breathing: Contrasting brain and autonomic responses(Ruiz-Blais et al., 2026, PLOS One)

7. Music structure determines heart rate variability of singers (Vickhoff et al., 2013, Frontiers in Psychology)

8. Prevention of upper respiratory tract infections by gargling: a randomized trial (Satomura et al., 2005, American Journal of Preventive Medicine)

9. Vitamin D3 and gargling for the prevention of upper respiratory tract infections: a randomized controlled trial (Goodall et al., 2014, BMC Infectious Diseases)

10. Humming greatly increases nasal nitric oxide (Weitzberg and Lundberg, 2002, American Journal of Respiratory and Critical Care Medicine)

11. Induction of nitric oxide via humming does not improve short-term cognitive performance or influence emotional processing (Francis et al., 2024, PLOS One)