Adele credits sound baths with getting her through her hardest year. Meanwhile, MIT is running a phase III trial on sound as a treatment for Alzheimer’s disease. Is sound healing legit?
In the fall of 2021, Adele appeared on the cover of British Vogue and American Vogue simultaneously — the first time the sister publications had shared a cover star — to explain, at some length, where she had been. The album she was releasing, 30, documented a divorce, a custody arrangement, and a year of anxiety so sustained that she had spent most of it, by her own account, living like a recluse. Therapy helped. Exercise helped. A great deal of time alone helped. So did, she told both magazines, a significant quantity of sound healing. “It was a lot of sound baths,” she told Vogue. “It was a lot of meditation. It was a lot of therapy. And a lot of time spent on my own.” The album sold more than a million copies in its first week. The detail about the sound baths was hardly mentioned.
That same fall, in a laboratory at MIT’s Picower Institute for Learning and Memory in Cambridge, Massachusetts, a neuroscientist named Li-Huei Tsai was working on a device that delivered sound — and light — at precisely 40 oscillations per second, the frequency of the brain’s gamma waves, and finding that daily exposure to this engineered signal was producing measurable changes in the brains of Alzheimer’s patients: amyloid clearing, tau proteins declining, cognitive function holding at levels significantly higher than comparable patients in national databases. Tsai’s technology, called GENUS — Gamma Entrainment Using Sensory Stimulation — had been licensed to a company called Cognito Therapeutics and had entered a pivotal, nationwide phase III clinical trial. It used, among other things, sound. It was not, in the hotel spa sense, sound healing.
From the bowl to the body
The history of therapeutic sound covers several continents and several thousand years. Ancient Greek physicians prescribed musical modes for specific ailments; Pythagoras called music the cure for disturbed passions of the soul. The Aboriginal peoples of Australia have used the yidaki — the instrument the world calls the didgeridoo — as a healing tool for more than 40,000 years; the drone it produces sits between 40 and 65 Hz, a frequency range that appears in the current research literature with notable regularity. The classical Indian Raga system assigns specific melodic frameworks to times of day and physiological states — ragas for morning, for grief, for concentration, for the hour before sleep — on the explicit premise that sound at the right frequency affects the body in predictable ways. The Amazonian healing tradition uses icaros — sacred songs sung or whistled by curanderos during ceremony — as the primary vehicle for the healing process itself, the melody understood as medicine rather than accompaniment. Tibetan singing bowls have been in use for centuries; struck or circled with a mallet, they produce a sustained fundamental tone and a cascade of harmonics that can oscillate, depending on the size and alloy of the bowl, anywhere from 40 to 800 Hz.
The clinical version of this principle is called vibroacoustic therapy — a modality in which sound frequencies are delivered through a specialized table or lounger directly into body tissue, bypassing ambient listening and transmitting vibration mechanically through skin and bone. Diana Parra Perez, a PhD sound bath facilitator and mindfulness researcher at Washington University, has described the essential distinction: sound is not only perceived through the ear, but also by the body — an observation that explains why someone lying on a vibroacoustic table in a clinical setting and someone sitting cross-legged in a room with a Tibetan singing bowl are, in principle, receiving the same type of input at significantly different levels of precision and control. “There’s music everywhere, all around us. And it just takes that moment of mindfulness,” she said.
A 2024 study published in MDPI’s Healthcare journal measured the physiological effects of vibroacoustic therapy using simultaneous ECG and EEG monitoring and found increased parasympathetic nervous system activity in all participants, alongside measurable EEG shifts: increased concentration, reduced arousal, increased relaxation. These are the same physiological markers that a week of wellness programming is designed to move. A single vibroacoustic session moved them in under an hour. A few months later, Nature Biotechnology ran a feature titled “Sound healing and beyond.” The sound bath is not, it turns out, a metaphor.
“The medical community rarely considers prescribing sounds as healing agents,” the researchers wrote. “Yet the technology and its potential to treat certain conditions have been known for decades.” The researchers looked at ultrasound neurotechnologies, which are moving into clinical trials for a wide variety of applications.
“It is not clear exactly how all these therapies work,” the researchers wrote. “Some hypothesize that mechanical forces disrupt the cellular membrane conformation, leading to polarization and activating channels or proteins embedded within; others point at evidence suggesting that the ultrasound could directly cause membrane channels to activate. The reality is likely to be combinations of these mechanisms in different tissues.”
The brain’s gamma oscillations — neural rhythms running at approximately 40 Hz — are involved in memory consolidation, attention, and cognitive processing. In Alzheimer’s disease, these oscillations weaken and desynchronize early in the disease progression; the cognitive decline that follows is, in part, a downstream consequence of this disruption. Tsai’s research began with the question of whether driving the brain back into gamma synchrony through sensory input might interrupt that process. The mechanism is specific: 40 Hz light and sound stimulation activates the brain’s glymphatic system — the waste-clearance pathway that operates primarily during sleep — which then flushes amyloid and metabolic debris from neural tissue. The mice, at first. Then the humans.
A 2025 paper published in the journal Alzheimer’s & Dementia tracked five volunteers who continued daily 40 Hz audiovisual stimulation for approximately two years after participating in an early-stage MIT clinical study. Three of the participants — all women with late-onset Alzheimer’s disease — showed cognitive measures significantly higher than those of comparable Alzheimer’s patients in national databases; tau protein levels in two of those volunteers had measurably declined. The paper’s authors wrote that “daily 40Hz audiovisual stimulation over 2 years is safe, feasible, and may slow cognitive decline and biomarker progression, especially in late-onset AD patients.”
In March 2025, MIT published a broader review documenting how the evidence base for 40 Hz gamma stimulation had expanded across labs worldwide since the original mouse-model findings. Tsai told MIT News that the outcomes reflected something she had been building toward for a decade: “People who continued with this treatment, their memory capacity really has been maintained at a steady state level. And in a couple of patients, their Alzheimer’s biomarkers actually significantly reduced.”
“People have used many different ways to induce gamma,” Tsai said in the review, “including sensory stimulation, transcranial alternating current stimulation, or transcranial magnetic stimulation, but the key is delivering stimulation at 40 hertz. They all see beneficial effects.” The sample sizes remain small enough to require interpretive caution. The device itself looks nothing like a spa treatment: it resembles a large pair of goggles that flicker at 40 Hz, paired with speakers playing a 40 Hz tone, used for one hour a day at home.
Where to experience sound healing
In September 2024, Six Senses — a wellness hotel brand with more than two dozen properties across 22 countries — formalized sound therapy into its global programming, adapting the modality at each property to local traditions and instruments rather than standardizing a single menu. Six Senses La Sagesse in Grenada installed a full-body vibroacoustic lounger for sound immersion sessions, the frequency delivered through the body rather than through the air. Six Senses Fiji built a sound journey around Fijian and oceanic drumming rhythms. Six Senses Kaplankaya in Turkey and Six Senses Kyoto in Japan introduced Watsu — aquatic bodywork performed in heated pools — combined with live sound healing. Six Senses Vana, on 21 acres in the Himalayan foothills of Uttarakhand, India, added Raag therapy: classical raga performed live on the flute, with each melodic framework assigned to a specific time of day and a specific physiological state of the body, in the tradition of therapeutic Indian classical music that predates modern medicine by several centuries.
Six Senses Vana’s programming is built around a minimum seven-night stay, on the premise that the body needs more than a weekend to register a genuine shift. The Raag therapy sessions are integrated into longer wellness programs rather than offered as standalone bookings; rooms are available year-round. Amangiri, the 34-suite canyon resort in southern Utah, includes sound bowl therapy as part of its programming, nested into days that begin before dawn and are organized around the silence of the Colorado Plateau — a landscape that produces measurable cortisol reduction independently of whatever is happening in the treatment room. The canyon does some of the work before the bowl is even struck.
What all of these programs have understood, at varying levels of clinical precision, is a version of what Tsai’s lab has been documenting in journal papers for a decade: the body is responsive to frequency in ways that are physiologically real, and the context in which that frequency arrives — a quiet canyon, a Himalayan hillside, a renovated estate in Grenada with a view of the Caribbean — is not irrelevant to the outcome.
The useful question before booking is a straightforward one: is this a sound bath — singing bowls or gongs, ambient listening, passive receiving — or vibroacoustic therapy delivered through a specialized table? The first will reliably produce relaxation. The second has more specific nervous system effects backed by recent peer-reviewed data. Six Senses Vana’s Raag therapy belongs to a third tradition — a centuries-old framework with its own internal logic about the relationship between sound, time of day, and the body’s states — that the wellness industry has been slowly learning to take seriously on its own terms, rather than forcing it to justify itself in the vocabulary of ECG readings and cortisol panels.
Adele did not specify which kind of sound bath she had been using during her year of anxiety, or what frequency the bowls were tuned to, or whether the sessions were individual or group. She only said it helped. Given what the research now shows about what happens inside a body in the presence of sustained low-frequency vibration — the ECG, the EEG, the parasympathetic activation, the cortisol — the more surprising answer would have been if it hadn’t.
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