Sleep And Vagal Tone: Your Vagal Nerve Might Be The Key To A Great Night’s Sleep And Better Health…

Ever watched a video or listened to a recording of soft and soothing sounds like Tibetan singing bowls, wind chimes, or even cascading surf on a beach? Why is it that we are soothed and feel a wave of relaxation pouring over us when we listen to these sounds? The answer might be more grounded in human anatomy and physiology than we were aware.

The Vagus nerve is the longest cranial nerve in the body, often referred to as “the silver cord” as far back in time as 4,000 years. Originating in the  brain and extending all the way down to our internal organs, it is the primary regulator of the parasympathetic nervous system, which controls all of our involuntary systems, such as digestion, heartbeat, respiration, even our fight or flight response. It is responsible for controlling the release of hormones that induce relaxation after a highly stressful event (the sympathetic nervous system’s activation).

Your vagal tone can be quantified and determined by a particular characteristic condition of your heart, known as heart rate variability. Heart rate variability is not the same as your heart rate. It is a measure of the intervals between your heart beats.

All people have some degree of arrhythmia in their heart rate patterns, which is totally benign. Your heart rate typically speeds up when you breathe in, and slows when you breathe out (also known as respiratory sinus arrhythmia). The larger and smoother these waves in your heart rhythm are, the better vagal tone you have, and the more relaxed you will feel.

Stress causes these wave forms to become more compressed, irregular, and shorter. Sustained compression of heart rate variability is typically a sign of poor conditioning. In today’s world, stress tends to be chronic in nature, and many people are perpetually trapped in a state of low vagal tone, resulting in poor sleep habits and reduces the ability to thrive. Increasing your heart rate variability causes your vagus nerve becomes more activated and responsive. This will help you manage all kinds of life issues better, including your ability to fall asleep quickly and deeply. Try deep breathing exercises to improve your vagal tone.

Interestingly, the vagus nerve has a more primordial, or older evolutionarily component, called the “dumb” vagus, that can dissociation, instant immobilization or a “freeze” reaction, which helps when a threat, such as a predator, is moving in for the kill. The newer part of the vagus, called the “smart” vagus, assists in dialing down stress, enabling you to engage in otherwise fearful interactions like public speaking or managing your way through a rescue attempt or escaping from a fire, as examples. This so-called smart vagus mechanism can be bolstered and invigorated manually, enhancing your ability to control your responses in complex and threatening scenarios.

Exercising your vagus nerve, which improves vagal tone, can make you more adaptable to virtually any life situation. By conditioning your nervous system, you can process stress more smoothly, and dial it down quickly, thus removing stressor hormones from your body.

Vagal tone typically deteriorates with age, like many other organ systems and processes, but it can be measured by the variations in the heart rate between inhalation and exhalation. During inhalation, the heart speeds up, but during exhalation, it slows down, taking a subtle pause between beats. You can do it right now, as you are reading.

Sit upright and try to relax for a moment. Place your index and middle finger from your right hand on the wrist of your left arm. Take a deep, lung filled breath while you are monitoring your pulse, and exhale. You’ll notice that on your exhale, your heart rate will slow. If you can notice this response, this means that you have good vagal tone. If you cannot, then your might be in need of some easy therapy to help reset your vagal tone


The ear and hearing have an enormous effect on the human body because of their proximity to the vagus nerve. Known as the tenth cranial nerve, the vagus nerve itself does not play an active part in the process of hearing. Beyond the medical field, we don’t rely on hearing and our ears for much more than processing sound and warning us of impending danger, enjoying music, and hearing that enjoying crunching sound while eating. 

The vagal nerve is connected with the posterior wall of the external auditory canal, the lower part of the eardrum’s membrane and in the middle ear adjacent to the stapedius muscle. It’s strangely intertwined with this muscle, and from this vicinity in the ear, it descends directly down to the lower internal organs and is responsible for a high number of regulatory functions in throat, chest, and abdomen. It has an incredible impact on the heart, vasculature, neurological functions, endocrine glands, and much more.

Essentially, though, stimulating the ear with specific sounds means stimulating all of our vital organs. the reason why for this might be fairly simple. Once upon a time humans were prey, and hearing became our first line of defense, probably more important than sight, since we could detect predators from a distance. Through millions of years of evolution and natural selection, our hearing became hardwired to immediately set the body into fight our flight response mode, but also, our bodies became accustomed to soothing and calming noises, too, and we seek out those calming effects when we want to retreat to our nests and sleep.

The ear is in fact a parasympathetic regulatory organ that uses innervation of the vagus nerve to regulate the whole body. The vibrations caused by sound tend to have a very significant impact on virtually all areas of the body that are connected to the vagal nerve. Further, the majority of cranial nerves are either directly or indirectly connected with the ear.

Because of the effect that sound has on the body, especially at certain frequencies, certain objects and instruments such as tuning forks and Tibetan singing bowls can be instantly calming and relaxing, helping the body to return to the calm and soothing state that the “fight or flight” mode creates after being triggered by stress. In fact, lower frequency sounds that are long and sustained, tend to be soothing and relaxing (called a parasympathetic response) whereas shrill, sharp and abrupt sounds tend to trigger alertness and alarm (sympathetic response). Imagine being stalked by a velociraptor- it certainly won’t sound like a calming waterfall, or a the sound of distant rumbling thunder far off on the horizon.

Another amazing phenomenon is that auditory stimulation of the vagus nerve can result in reduced activity of the limbic system. The limbic system, located on both sides of the thalamus, includes the hypothalamus, the hippocampus, and the amygdala, all in what is known as the forebrain, beneath the larger cerebellum and cerebrum. This area of the brain is primarily responsible for our emotional life and has a lot to do with the formation of memories. It keeps us alert, processing immediate environmental changes, deciphering and responding to threats, and generally keep our minds aware of our surroundings. But it also can be manipulated or “massaged” by very particular stimuli so that we can calm ourselves, relax, and even drift off to sleep. 

ASMR videos, calming music that is sleepy and generally at lower frequencies, the sound of a soothing voice, are all processed by the vagus nerve and handed off to our organ systems and other parts of our brain which then promote the release of hormones like serotonin and dopamine, which are “pleasure” hormones. These hormones are powerful, and offer incredible healing benefits for the body as well.


Incredibly, The simple practice of toning, producing long sounds that vibrate, as well as humming, can have perceptible calming effects by virtue of its auditory stimulation of the vagus nerve, which in turn causes limbic deactivation. Ever watched someone who is humming a song to themselves or is momentarily entranced and light years away while listening to music or the sound of someone talking? Their vagal nerves are working, so hush! 

For sleep, listening to calming sounds is an incredibly effective way to get your body to relax and begin to drift off.  The auditory system related nerves begin to work while we are still in utero. The acoustic nerve known to begin covering itself with its protective myelin sheath around the sixth month of pregnancy,  whereas the neocortex only completes myelination about 12-14 years later. Myelin is the coating substance that isolates the nerves and enhances the transmission of electrical signals, like the sheathing around a copper wire.

At birth mammals have fully developed auditory processes, again likely due to the evolutionary pathway that refines creatures who can immediately respond to cues when being attacked by predators when threatened, and survive. Infants are known to become quiet and still when they hear a threatening sound, if not for a few moments while their mothers quickly remove them from the threat.

Also, the area in the temporal lobe of the brain where auditory signals are received and processes is functional before birth. Even the inner ear reaches full adult size. A fetus, floating in water within its mother, can process invigorating signals from the outside world, including its mother, while still unborn.

Other important nerves that are connected to the ear include:

  • The trigeminal nerve (fifth cranial), which branches out to muscles in the middle ear, receiving signals from the eyes, nose, sinus, jaw, teeth, lips, cheeks, hard palate, tongue. It is also responsible for head sensations.

  • The facial nerve (seventh cranial), connected to the ear canal and responsible for facial expressions and opening and closing the  mouth.

  • The glossopharyngeal nerve (ninth cranial) is attached to the eustachian tube and the ear, and is responsible for sensations in the pharynx, soft palate, tongue, tonsils, also assisting with the reflexes of respiration, blood pressure, and heart rate.


Difficulty falling asleep (sleep induction) and then remaining in a deep, restorative level of sleep can be caused by many things, one of them of course, being a terrible mattress. But failure to get deep sleep, where you are actively dreaming, can be improved by increasing your vagal tone.


Trouble sleeping can interfere with lucid dreaming too, which is a byproduct of deep, energizing sleep. A sufficient amount of sleep is necessary for lucid dreaming because the bulk of your REM sleep, the stage where vivid dreaming occurs, generally in the second half of your sleep cycle.

Improving the quality of your sleep and developing sleep-promoting habitats and techniques can help you get the best sleep possible. Often, sleep disorders and psychiatric conditions can cause insomnia to be worse, so addressing those issues may help improve the quality of your sleep, Learning deep relaxation skills is another powerful way to help you drift to sleep quickly, particularly skills that efficiently target the vagus nerve.

The vagus nerve has an evolutionarily older component, called the “dumb” vagus, that influences dissociation, immobilization or “freeze” responses. The newer part of the vagus, called the “smart” vagus, helps you down-regulate stress and engage in social interactions effectively. The smart vagus circuit can be strengthened voluntarily to enhance your capacity for self-regulation and connection with others. Exercising your vagus nerve, and improving vagal “tone,” can make you more flexible and adaptive in responding to cues in your environments. By “toning” your nervous system, you can buffer against stress and recover faster from it.


Breathing with your diaphragm at a slow pace and rhythm can enhance how much your heart rate accelerates and decelerates with each breath, improving the tone of your vagus nerve.

Most people breathe between 12-20 breaths per minute. With this technique, you slow your breathing rate to about 6 breaths per minute. This creates a resonance effect between your heart rate, breathing, and blood pressure, maximizing your heart rate variability.

This state often induces a feeling of ease, relaxation, a loosening of muscle tension, and if you are sleep-deprived, sleepiness. It can be practiced intermittently in the daytime to lower your baseline levels of stress, and as you strengthen your vagal tone, it can be applied to soothe and calm yourself whenever needed. The more you practice this breathing technique, the stronger and smarter this reflex of your vagus nerve can become.

Here’s how you can learn this technique.


The first step to learn resonant frequency breathing is to train yourself to breathe with your diaphragm so your abdomen expands with the inhale and deflates with the exhale.

Have you ever seen a newborn baby breathe? Infants do not yet have the ability to breathe shallowly in their chests because they lack tone in their accessory breathing muscles. Thus, little babies breathe entirely using their diaphragm, the muscle that separates your chest and abdominal cavities and helps you breathe automatically.

Most adults tend to chronically breathe shallow in their chest. This is a natural response to navigating higher levels of activity and stress in life. However, people still chest breathe even when they’re not facing significant stressors, making their recovery from life’s challenges more slow, or even absent.

Place one hand on your chest and one on your belly, and inhale. Does your chest rise when you breathe in? Or is your breath more centered on your diaphragm so your belly inflates when you inhale?


To breathe with your diaphragm, allow the air to enter all the way to the bottoms of your lungs, so that your diaphragm pushes your belly out when you breathe in, and allows your belly to deflate when you breathe out. Make sure your chest stays completely still as you breathe abdominally.

For about one week, practice this for 10 minutes per day. Do this without slowing the pace of your breathing just yet.

Paced Breathing

Once you are comfortable with diaphragmatic breathing, gradually slow your breathing rate until it reaches about 6 breaths per minute. This means you will eventually learn to inhale for 5 seconds, and exhale for 5 seconds. Or, you can inhale for 4 seconds, and exhale for 6 seconds.

Some find it more comfortable or relaxing to breathe at a slightly faster or slower rate than 6 breaths per minute. Experiment with different rates to find a pace that works for you. But keep in mind that, on average, most people achieve a state of resonance when breathing at 6 breaths per minute.

If you have difficulty slowing your breathing pace, then slow it only as much as you are comfortable. With time and practice, you can gradually and comfortably achieve a slower pace until you are breathing at a rate of ~6 breaths/minute.

Practice for at least 10 minutes consecutively every day.

Use Breath Pacers

A visual or audio pacer can help you focus on pacing your breathing better compared to counting the lengths of inhalations and exhalations. For visual pacers, inhale when the pacer ascends or expands, and exhale when the pacer descends or diminishes. If you use an audio pacer, inhale when the tones ascend, and exhale when the tones descend.

There are also home-training biofeedback devices, such as the emWave device by Heart Math, that can help you target and maximize your heart rate variability with more accuracy.

Breath pacers are great training tools. But ultimately, you will want to be able to pace your breathing intuitively on your own so you can easily apply this skill whenever needed.


When you are trying to fall asleep, apply the practice of paced breathing at ~ 6 breaths per minute. When this is applied in the context of good sleep habits, it can help you fall asleep faster.

Couple this technique with meditating on your senses, such as your breathing, without judging your experience. This will help you avoid thinking of things that can activate your brain too much and make it harder to fall asleep. In other words, you can induce positive, bottom-up (paced breathing) and top-down (meditation) influences on your nervous system to eliminate or reduce insomnia.

Daytime Diaphragmatic Breathing

It is best to set at least 10 minutes aside to formally practice paced diaphragmatic breathing during the day. This can reset, balance, and tone your nervous system in ways that positively influence your overall ability to navigate reality.

It can also help to engage in a less structured practice of diaphragmatic breathing. This works by becoming aware of your breath multiple times per day, and shifting your breath from your chest to your abdomen. You can do this at idle points, whenever you think of it, or if you notice your levels of stress and arousal are higher. Feel free to also slow the pace of your breathing, if that feels comfortable, for at least a few breaths.

This down-regulation of the nervous system can lower your baseline levels of stress and hyper-arousal. This not only helps your decision-making and functioning while awake, but it can make it easier to down-shift into a state of restful sleep at the end of the day.


Paced diaphragmatic breathing comes more easily to some than others. But committing to the practice and being patient can make your learning process smoother.

The following includes a few problems commonly observed in those new to the technique, and how to overcome them. Pros that offer heart rate variability biofeedback therapy in your area may also be able to help you.


Some people feel lightheaded when they first start practicing paced breathing. If this happens to you, make sure you are lying down when you practice. It also can help to purse your lips when you breathe out to combat any dizziness. With practice, this feeling will eventually go away and breathing with your diaphragm will feel more natural and easy.

You can’t breathe abdominally

You might discover that it is too hard for you to breathe such that your abdomen rises on the inhale instead of your chest. However, you should know that you already breathe with your diaphragm whenever you are in deeply relaxed states, such as when you are falling asleep or perhaps after you eat a big meal.

If you’re still having trouble, don’t give up. Instead, try practicing when you are laying down flat and already in a relaxed state. You will see that you naturally breathe abdominally when you are naturally relaxed. Once you feel more confident in your ability to breathe like this, practice the skill in other situations, too.

You don’t feel relaxed

Most likely, you are not practicing paced breathing enough. Your vagal reflex is a bit like a muscle. You need to exercise it regularly and repetitively in order for it to get stronger. The rule of thumb is to practice paced diaphragmatic breathing at least 10 consecutive minutes per day. While this is usually enough to do the trick, sometimes people require 20 minutes of daily practice to notice results.

You also may discover it‘s difficult for you to remember to practice for long, or to find the time to practice at all. In that case, try scheduling this practice at points you will be likely to do it, such as at bedtime. You can also split your 10 minute goal into smaller chunks of time throughout the day. Practicing a few minutes occasionally is more helpful than not practicing at all.

You also might not be practicing the skill correctly. A frequently seen error is only practicing this technique when you are stressed in order to calm yourself down, which doesn’t work well if you haven’t mastered the skill yet. Instead, you should practice when you are already in a relatively relaxed state, which will allow you to stretch and strengthen this response in your vagus nerve best. Once this reflex gets stronger, you will be able to induce relaxation quickly whenever you apply the skill, including during times when you are more stressed.

Take-Home Points

To lucid dream, you need to sleep deeply and easily, and get enough sleep. If you struggle with insomnia, a potent technique for inducing relaxation and sleep is to train the rhythms of your vagus nerve, which is responsible for relaxing your mind and body.

Activating your vagus nerve can be achieved through a variety of relaxation techniques. Compared to most standard, relaxation techniques, diaphragmatic breathing at a 6 breaths/minute pace is more efficient at targeting and maximizing vagal activity, and thus, inducing states of relaxation and sleep. This is because paced breathing creates a resonance effect in your heart rate variability, an index of your vagal tone.