Extracted from "The practice of Nada Yoga" by Baird Hersey.
Here is the meditation with the additive practices integrated in, with instructions for each step.
Take a couple of deep slow breaths, with equal inhale and exhale. Then let your breathing settle into a relaxed, easy flow.
Sit comfortably with your body in symmetry. Let the right side of your body (hands/arms, feet/legs) be in the same position as the left side. If you can sit with your legs crossed with one of your heels pressing up into your perineum, that is ideal. If not, sit on a rolled up blanket or pillow with your legs on both sides so that there is pressure on your perineum. Block the sound entering your ears with earplugs. You can use your fingers instead, although this will cause a sound of its own, which may be distracting.
Put your hands on your knees. This will prevent you from slumping. Keep your spine straight. (If your fingers are in your ears, sit with your feet flat on the ground and your knees up. Put your elbows on your knees.)
Rest your tongue on the front of the roof of your mouth with the tip resting lightly on the ridge just above the roots of the upper teeth.
Close your eyes.
Lightly engage mula bandha, by contracting the PC muscle, and uddiyana bandha, by pulling the belly in and the navel up. This will help the energy move up from the perineum, passing in front of the spine, all the way to the top of the head.
Try to find a position of comfort so you don’t have to move. You want to be able to sit in perfect stillness in order for yoga nidra to arise.
Recall a past experience of unconditional love. Fill your heart with that feeling. Repose in the center of your heart, suffused with that unconditional love.
With your eyes still closed look up between your eyebrows. Your gaze is inward, but your focus is as if you were looking outward into the distance. Although you are actively looking/watching, try to make this effortless, without strain.
With a feeling of unconditional love and sense of joyful anticipation, invite the Divine Light to arise.
Allowing the light to arise is something we intuitively and naturally know how to do. The light is already shining within us. With unconditional love surrender your control over it.
Quiet your mind. Let go of all thinking. If thoughts come up, let them pass like a cloud in the sky. Then bring your focus back to looking/ watching between your eyebrows.
If you continue to be distracted by your thoughts, chant So on the inhale and Ham on the exhale, or Om, or a personal mantra. If you would rather use a word in English that is meaningful, One or Love will work nicely. Repeat it both on the inhale and the exhale.
At first you may see only darkness. Eventually you will begin to see flickering, clouds, rays of color, or lights. These are not imagined. They are an internal perception.
If light arises, hold it in your attention without trying to control it. Thank it with unconditional love for arising.
With continuous unbroken concentration, over time, the lights will eventually become a single focused point of light. It may be a very small, intense dot or fleck of light, an iridescent blue or indigo “pearl” surrounded by a corona, a bright burning ball of white light, a shimmering star, or other concentrations of brilliant radiance.
Realize that you are not separate from the light. Embrace that “You are that.” Co-absorb with the 8. At the same time draw your eyes back in toward the center of your head, pulling the light with them.
Draw the light into and around you. As you dissolve into it and it into you, blissfully feel it surrounding and covering your head. Let that blissful feeling flow over and spread through your entire body.
Keep a continuous feeling of moving forward into the light as it is drawn into you and you are drawn into it.
Your body should feel extremely comfortable. Remain perfectly still to maintain that blissful comfort.
Now that your attention has steadied, let go of any mantra you might be using. This clears the way for listening for the internal sound. The light leads the way to the sound.
There is a subtle nerve channel that runs from under the right eye, down the cheek to the bottom of the jawbone, along the lower jaw to its hinge, and back up behind the right ear. Turning your attention to this nadi will lead you from the light to the sound.
With a feeling of unconditional love and joyful anticipation, invite the Sacred Sound to arise.
Allowing the sound to arise is something we intuitively and naturally know how to do. The sound is already vibrating within us. With unconditional love, surrender your control over it.
Listen through the right ear for an internal sound. The sound may take many forms: a low rumble, a buzzing, a resonant sustained tone, a shimmering tinkle, or a high ringing. If you don’t hear any of these right away, be patient and wait with a joyful anticipation for the sound to arise. Allow for the possibility that in time you will hear it.
If sound arises, hold it in your attention without trying to control it. Thank it with unconditional love for arising.
It is a very subtle sound. Whatever sound you hear fix your attention on the subtlest part of it: the sound behind, above, within, or beyond the sound. Just by focusing on it, it will increase in intensity and volume.
Follow the sound, co-absorb with it, letting it pour into you, filling you like water from a pitcher.
Having co-absorbed with both the sound and the light, realize you are not separate from them. You and the light are one. You and the sound are one. The light is the sound. The sound is the light. You and the light and the sound are all merged. Dissolve into them and them into you. You are all one.
Look straight ahead, “through” your eyelids, as if you are looking at a point far in the distance. You may experience a vast openness, a distant horizon, an expansive pale white sky.
On the inhale draw the breath/energy up from the perineum, up the spine, all the way to the top of the head. On the exhale let it release back down.
Dissolve the light, sound, breath/prana, and your mind all into one.
Remain perfectly still in your body and mind.
When you are finished rub your head, arms, torso, legs, and especially the bottoms of your feet.