The 2002 experiment
Eddie Weitzberg and Jon Lundberg published a brief report in the American Journal of Respiratory and Critical Care Medicine. They asked ten healthy people to breathe out through the nose two ways, quietly and while humming, and measured the nitric oxide coming out.
During humming, nasal nitric oxide was about fifteen times higher than during a quiet exhale. The paper's title says it plainly: humming greatly increases nasal nitric oxide.
Why it goes up
The team's explanation lies in the paranasal sinuses, the air-filled cavities around the nose. Nitric oxide builds up there, and each sinus connects to the nose through a small opening. In a two-compartment model, they saw that oscillating airflow, like the kind a hum produces, greatly speeds up the exchange of gas between the two spaces.
Put another way: the hum doesn't manufacture the gas on the spot. It shakes the air and empties into the nose what was already stored in the sinuses.
What came next
In 2003, the same group repeated the measurement in more detail, again in ten healthy people. Nitric oxide spiked at the start of the hum and then declined. With repeated hums the peak got smaller each time, and it recovered after three minutes of silence. That fits the picture of a reservoir that empties and refills. The size of the sinus opening was the factor that mattered most, and the pitch of the hum mattered too.
From the start, the authors had a test in mind, not a health exercise: measuring the humming peak to find out whether the sinuses are ventilating well. In a 2004 pilot study of 59 people with allergic rhinitis, those who showed no peak were far more likely to have blocked sinuses. Another team, in 2012, didn't find that relationship in 33 people. The test is still under study.
What the study doesn't show
- It doesn't show a health benefit. It measured a gas in nasal air for a few seconds, in ten healthy people. The authors themselves wrote that the possible effects of better sinus ventilation deserved study, meaning they hadn't been studied.
- It doesn't show your body making more nitric oxide. It shows more of what was already there coming out. With back-to-back hums, the peak drops.
- It says nothing about infections or sinusitis. What circulates on that front rests on a single case report published in 2006 as a hypothesis, with no comparison group.
- It doesn't show effects on the mind. In 2024, four experiments tested whether humming improved attention, memory or the processing of emotions. They found no improvements, and on two tasks humming got in the way.
And the bee breath
Bhramari is on the list of eight kumbhakas in the Hatha Yoga Pradipika, the classic manual of hatha yoga. Its verse speaks of a hum like a bee's and of a kind of ecstasy in the practitioner's mind. The tradition doesn't talk about gases, and it doesn't need them to make sense.
On bhramari as a practice, a 2018 systematic review found just six studies, with groups of 8 to 84 people, measuring different things: blood pressure, heart rate, brain activity, reaction time and tinnitus distress. The reviewers call the results encouraging and rate the quality of the studies as very low. None was a randomized trial, and the review doesn't mention nitric oxide.
There's a simpler reason humming tends to feel good. To sustain the sound, the air has to leave slowly and evenly. Humming is a way to lengthen your exhale without counting.
How to try it
In Bhramari, the bee breath, you breathe in through your nose for 4 seconds and hum with your lips together for 8, for 3 minutes. A low, soft sound lasts longer and tires you less than a loud one.
If you like the long exhale but prefer silence, Long exhale 4-8 has the same timing. Ujjayi, the ocean breath uses a different sound, a soft rasp in the throat.
If you feel dizzy or short of breath, stop and breathe normally. If you have ear or nose pain or an infection, wait until it clears. And if you have congestion that won't quit, frequent sinusitis or any symptom that worries you, that's a conversation for a health professional: humming is not a treatment.
Frequently asked questions
Does humming increase nitric oxide?
In the air in your nose, yes. A 2002 study of ten healthy people measured about fifteen times more nasal nitric oxide during humming than during a quiet exhale. The explanation is that the hum moves gas stored in the paranasal sinuses out into the nose.
Does humming help with sinusitis?
No trials show that. The research used humming as a possible test of how well the sinuses ventilate, not as a treatment. If you have sinusitis symptoms, talk to a health professional.
How long should you hum?
No amount has been studied as best. In the measurements, the nitric oxide peak dropped with repeated hums and recovered after a few minutes of silence. As a calming practice, the bhramari session on this site lasts 3 minutes.
Is humming the same as bhramari?
Bhramari is humming inside a slow breath: you breathe in through the nose and let the air out with a long hum, lips closed. The nitric oxide experiments measured individual hums, not the yoga practice.
Does humming have proven benefits?
What's proven is the rise in nitric oxide in nasal air. The health benefits often attached to that finding haven't been demonstrated. Studies of bhramari are few and of very low quality, though people who practice it tend to describe it as pleasant.
Sources
- Weitzberg and Lundberg 2002, Humming greatly increases nasal nitric oxide (Am J Respir Crit Care Med), abstract
- Maniscalco et al. 2003, Assessment of nasal and sinus nitric oxide output using single-breath humming exhalations (European Respiratory Journal), abstract
- Maniscalco et al. 2004, Humming-induced release of nasal nitric oxide for assessment of sinus obstruction in allergic rhinitis: pilot study (Eur J Clin Invest), abstract
- Shusterman et al. 2012, humming, nasal nitric oxide and sinus patency (Am J Rhinol Allergy), abstract
- Eby 2006, case report on chronic rhinosinusitis and humming (Medical Hypotheses), abstract
- Francis et al. 2024, four experiments on humming, cognition and emotion (PLoS One), abstract
- Hatha Yoga Pradipika, chapter 2 (verses 44 and 68), 1914 English translation, Wisdom Library
- Kuppusamy et al. 2018, Effects of Bhramari Pranayama on health: a systematic review (J Tradit Complement Med)