Sound and breath: why an audible rhythm helps

Breathing lets rhythm lead

In 1986, Haas, Distenfeld, and Axen published an experiment in the Journal of Applied Physiology with 20 people, half of them musically trained. They listened to a metronome and to four pieces of music, five minutes each, sometimes tapping along to the beat.

Their breathing got more regular. The variation in the length of each breath, 23 percent at rest, dropped to 15 percent while listening and to 10 percent while listening and tapping. In half the participants, breath length tracked the rhythm of the music. In twelve, breaths and beats locked into whole-number ratios, though not consistently.

The researchers proposed that musical rhythm can act as a pacemaker for breathing, and a stronger one the clearer the signal. It's a small study, and decades old. But it's a fair description of what an audio guide does: a clear, repeated signal that your body goes along with.

Tempo revs you up, silence lets you rest

In 2006, Bernardi, Porta, and Sleight measured 24 people, twelve musicians and twelve non-musicians, as they listened to six styles of music. Faster tempos and simpler rhythms raised ventilation, blood pressure, and heart rate. The musicians' breathing was more sensitive to tempo.

The surprise was in a pause. A two-minute silence was dropped in at random between pieces. During that silence, heart rate, blood pressure, and ventilation fell even below the starting baseline. The paper concludes that music arouses mainly through its tempo, and that relaxation is greatest during the pauses.

Two practical ideas follow. Music with a beat of its own can pull your breathing toward a different rhythm. And the silence between one cue and the next is doing its share of the work.

Prayers, mantras, and six breaths a minute

Your own voice sets a pace too. In 2001, the same group published a study of 23 healthy adults in The BMJ. When they recited the rosary or a yoga mantra, their breathing settled at about six breaths a minute, and the rhythms of heart rate and blood pressure synchronized with it. The sensitivity of the baroreflex, the mechanism that adjusts your pulse to your blood pressure, went up.

Six a minute is the pace of Coherent breathing 5-5. Nobody told those people to breathe slowly: the phrase did it, by lasting as long as it lasts.

The sound you make yourself

Some yoga breaths have sound built in. In Ujjayi, the ocean breath, you narrow your throat a little and the air sounds like the sea. That sound lets you hear whether your breath is even. A 2013 study of 17 beginners found that adding ujjayi to slow breathing didn't boost its effects on the baroreflex and in fact reduced them, possibly because of the extra effort.

In Bhramari, the bee breath, you hum as you breathe out. The hum stretches the exhale without any counting, because it lasts as long as the air does. In 2002, Weitzberg and Lundberg measured the air in the noses of ten healthy people: during humming, nitric oxide was fifteen times higher than during a quiet exhale. That's a finding about a gas, not a demonstrated health benefit.

The sounds in this guide

The sounds on this site are generated on your device and follow the same schedule as the animation. There are a few layers, and you can turn any of them off.

• Cues. A short sound goes with each phase: soft notes, bowl, wood, or glass. This is the layer that lets you close your eyes.
• Background. Ocean, wind, rain, or a steady tone, underneath the cues. You can also leave it on silence.
• Voice. A voice says each phase. It uses your browser's or your phone's voice, so it sounds different on every device.
• Tick every second. A light pulse for anyone who likes to count.

How to use them

• For sleep, dim the screen or flip your phone over and keep only the cues, at low volume.
• To learn a new exercise, turn the voice on the first few times and switch it off once you know the order.
• Around other people, practice with no sound: the visual guide is complete on its own.
• If a sound distracts or annoys you, change it or turn it off. There's no right sound.
• Don't use the guide while driving, with sound or without.