What is TRE™? The story of Dr David Berceli
Where TRE™ comes from, and why shaking is something your body already knows how to do.
ReadResources · Sound healing
Most sound healing sessions are made of instruments alone: bowls, gongs, chimes. Mine include something less common. Alongside the crystal bowls, I use my voice.
I'm a singer and voice-over artist, so my voice has always been one of the ways I express myself. But I didn't plan to bring it into sound healing.
I noticed that whenever I played the bowls, I naturally wanted to hum along. So I let myself. Over time I started to hone it: harmonising with the bowls, tuning my voice to their tones, to the vibrations in the room, and to the emotions I want to send out to the people lying in front of me.
What I found is that the voice adds something the bowls can't. The bowls create a beautiful field of sound. The voice makes it feel human, like someone is right there with you.
Much of my understanding here comes from Dr Stephen Porges and his polyvagal theory, which shapes how I think about everything to do with the nervous system.
Porges describes a process he calls neuroception: below conscious thought, your nervous system is constantly scanning for cues of safety or danger. You don't decide whether you feel safe. Your body decides first, and then your mind catches up.
One of the strongest cues of safety, according to polyvagal theory, is the human voice, especially its prosody: the melody, warmth and rhythm in how we speak or sing. Porges describes a social engagement system that links the muscles of the face, the middle ear and the voice box to the calming branch of the vagus nerve. When we hear a warm, melodic voice, the nervous system reads it as "I'm with someone safe", and it can begin to soften out of fight-or-flight.
We are wired to be calmed by each other. A warm voice tells the body it's not alone.
This is the heart of co-regulation: one nervous system helping another to settle. Long before we learn to calm ourselves, we learn to be calmed by someone else.
Think of how a baby settles at the sound of their mother's voice. That recognition starts remarkably early. In a classic 1980 study published in Science, researchers Anthony DeCasper and William Fifer found that newborns, only days old, preferred their own mother's voice over the voice of another woman. They had already learned it in the womb.
It makes sense, then, that a voice can ground us so deeply. It gives the body a felt sense of safety and connectedness that's older than words. Our nervous system reacts to sound in a biological way, not just an intellectual one.
Sound doesn't only shape how safe we feel. It can also shift the rhythm of the brain.
Our brain activity moves through different patterns, often described as brainwaves. Beta waves are linked with busy, everyday thinking. Theta waves are associated with deep relaxation, meditation and dreamlike states. Delta waves are the slowest, linked with deep rest and sleep.
In a small 2023 study, researchers Seong-Chan Kim and Min-Joo Choi recorded the brain activity of 17 adults lying with their eyes closed while a singing bowl was struck. Compared with each person's own starting point, theta activity rose by around 17% and delta activity by around 35%, peaking in the quiet after the final strike. The authors read this as a sign of deep relaxation, the kind of state where many people describe feeling peaceful and connected.
It was a small study, so it's a hint rather than proof. But it matches what I see in sessions: breathing slows, faces soften, and people often tell me afterwards that they drifted somewhere quiet and spacious.
When I tune my voice to the bowls, I'm offering two things at once. The bowls invite the brain to slow down into rest. The voice tells the body it's safe enough to go there, because someone is with you.
That combination is what makes my sessions feel the way they do. It's not a performance, and there's nothing you need to do. Simply lie down and receive.
Want to experience it?
Read more about sound healing sessions, or book a free exploration call to ask me anything.
Where TRE™ comes from, and why shaking is something your body already knows how to do.
ReadA first-timer's guide: what you'll do, what you might feel, and how you stay in control the whole time.
ReadAn honest account from my journal of my very first TRE™ session, and what has shifted since.
ReadPreparation, a checklist, what to wear, and where to place your laptop and phone.
ReadBook a free 15-minute exploration call. We'll chat about what you're hoping for, and whether TRE™ or sound healing is a good fit for your body right now. I usually reply within 1–2 days.