A research map, not medical advice — decisions go through a clinician.
Data current as of Jul 8, 2026.
Neural Entrainment
last expanded: Jun 28, 2026 · 4 entries
Alzheimer's Disease
Neural entrainment (40Hz gamma light & sound)
Spectris (Cognito Therapeutics)
Device
Phase 2 OVERTURE data showed slowed whole-brain and hippocampal atrophy plus preserved daily-function scores with daily 40Hz light/sound exposure vs. sham.
Bridge —Synchronized 40Hz sensory stimulation is proposed (Tsai lab, MIT, preclinical origin) to drive gamma oscillations that reduce amyloid/tau burden and support neural network synchrony; human trials are ongoing to confirm whether this translates into durable clinical benefit.
40Hz tone — the sound component of Spectris (the real device pairs this with 40Hz flickering light, not reproduced here).
Non-invasive, at-home device; flagship example of legitimate gamma-entrainment research, distinct in evidence base from unverified 'frequency healing' products.
FDA Breakthrough Device designation; pivotal Phase 3 (HOPE) ongoing
Phase 2 OVERTURE data showed slowed whole-brain and hippocampal atrophy plus preserved daily-function scores with daily 40Hz light/sound exposure vs. sham.
Bridge —Synchronized 40Hz sensory stimulation is proposed (Tsai lab, MIT, preclinical origin) to drive gamma oscillations that reduce amyloid/tau burden and support neural network synchrony; human trials are ongoing to confirm whether this translates into durable clinical benefit.
40Hz tone — the sound component of Spectris (the real device pairs this with 40Hz flickering light, not reproduced here).
Non-invasive, at-home device; flagship example of legitimate gamma-entrainment research, distinct in evidence base from unverified 'frequency healing' products.
FDA Breakthrough Device designation; pivotal Phase 3 (HOPE) ongoing
Small early studies show engagement of gamma-band EEG activity with light-only stimulation; clinical cognitive outcomes not yet established at scale.
Bridge —Uses the same 40Hz sensory-entrainment principle as Spectris (light without the synchronized sound component); mechanistic rationale is shared, but the clinical evidence base is much thinner at this stage.
Earlier-stage than Spectris — light-only approach with a smaller published evidence base so far.
No peer-reviewed evidence of any effect on amyloid, tau, or cognition.
528Hz tone — this is literally what the "Solfeggio" claim refers to. Hearing it doesn't confirm any of the claimed effects; see the flag above.
FLAGGED: pseudoscientific marketing claims ("528 Hz repairs DNA") with no clinical evidence. Included specifically to demonstrate the tier/evidence firewall — this is NOT the same category of science as device-based gamma entrainment (e.g. Spectris).
No registered clinical trials; consumer wellness product only
Meta-analyses support accelerated healing for established nonunions, but the large 2022 TRUST trial found no significant benefit over sham for fresh tibial shaft fractures.
Bridge —Low-intensity pulsed ultrasound delivers mechanical vibration to the fracture site, proposed to stimulate cellular signaling pathways (mechanotransduction) that promote osteoblast activity and callus formation.
One of the oldest FDA-cleared vibration/ultrasound devices in this catalog; a useful honest example of a legitimate mechanism whose real-world benefit is narrower than early marketing suggested.
FDA-cleared (1994) for nonunion and fresh fracture indications
Small studies report modest short-term reductions in pain and muscle tension; evidence base is limited to small samples without large RCTs.
Bridge —Low-frequency sound vibration is transmitted directly through body tissue, proposed to reduce muscle tension and modulate pain perception via mechanical and vagal pathways; the evidence base is still preliminary.
60Hz tone — representative of the low-frequency range used. The real therapy is felt through body contact (a chair or mat), not just heard through speakers or headphones.
Directly in the cymatics tradition — low-frequency (30-120Hz) sound vibrations delivered through speakers embedded in a chair or mat.
No large registered trials; used clinically in some pain and palliative-care settings
Some meta-analyses report modest reductions in pre-procedural and situational anxiety; effects on clinical anxiety disorders and sleep quality are inconsistent across studies.
Bridge —Two slightly different tone frequencies played separately to each ear are perceived by the brain as a single pulsing "beat" at the frequency difference, proposed to entrain EEG activity toward calmer brainwave states.
200Hz + 210Hz (a 10Hz beat) — headphones required. Through speakers both tones just mix in the air and there's no beat effect.
High study heterogeneity (frequency, duration, population) makes pooled conclusions difficult; widely available as a free consumer product with low risk.
Consumer audio product; studied in small clinical and healthy-population trials
Early pilot studies report reduced tremor amplitude and improved motor scores during and shortly after use; long-term and large-sample data are not yet available.
Bridge —Delivers brief, non-invasive vibratory pulses to the fingertips in a patterned sequence intended to desynchronize the pathologically synchronized neural firing associated with parkinsonian tremor.
Adapted from deep-brain-stimulation "coordinated reset" research into a non-invasive, wearable form — promising but still early-stage.
Small pilot studies; not yet commercially available or FDA-cleared
Pivotal trial results did not show a clinically meaningful benefit over control for chronic tinnitus loudness/distress, leading to commercial discontinuation.
Bridge —Delivered patient-tailored sequences of pure tones matched to the individual's tinnitus frequency, intended to desynchronize the pathologically hypersynchronized neural firing believed to underlie chronic tinnitus perception.
4kHz pure tone — representative of one tone in the sequence. The real device used a personalized multi-tone sequence matched to each patient's tinnitus pitch, not a single fixed tone.
Included specifically to represent failure honestly, per this catalog's design principle of not hiding terminated or negative results — a real, sound-frequency-based device whose evidence did not hold up.
Discontinued — commercially withdrawn (~2016) after disappointing pivotal trial results
A 10-patient cohort study found reversible blood-brain-barrier opening in hippocampal and cortical regions with no serious adverse events and an average 14% reduction in amyloid PET signal in treated regions; an earlier 6-patient pilot showed 2.7-10% reduction in amyloid PET SUVr.
Bridge —220kHz focused ultrasound is aimed at targeted brain regions to transiently and reversibly open the blood-brain barrier, proposed to promote clearance of amyloid or improve delivery of amyloid-targeting drugs.
Distinct from Exablate Neuro's separate, FDA-approved use for Parkinson's tremor (see that entry) — this Alzheimer's application remains investigational.
Not yet FDA-approved for Alzheimer's; multiple open-label Phase 1/2a trials completed or ongoing, some combined with anti-amyloid antibody therapy
In an 8-week trial in older adults, both 20Hz and 40Hz stimulation groups showed significant cognitive improvement on a standard battery; only the 40Hz group showed reduced depressive symptoms and increased EEG gamma power with enhanced auditory evoked-response amplitudes, consistent with gamma entrainment.
Bridge —Delivers 40Hz isochronous vibroacoustic pulses intended to entrain gamma-band brain oscillations, the same proposed mechanism as Spectris's light+sound approach, via a different sensory channel.
40Hz tone — this device's isochronous vibroacoustic stimulation frequency, the same target frequency as Spectris.
A newer, headset-based entrant in the 40Hz gamma-entrainment space alongside Spectris — vibroacoustic (felt and heard) rather than light+sound; still an early single-site trial awaiting replication.
Early-stage; double-blind RCT registered (Korea CRIS KCT0010055); not FDA-cleared
A sham-controlled pivotal trial (n=27) supported the FDA's 2018 approval, extending Exablate Neuro beyond its original 2016 essential-tremor approval to cover Parkinson's disease specifically; a large post-approval registry is now recruiting to track long-term outcomes.
Bridge —Focused ultrasound waves are aimed non-invasively through the skull to thermally ablate a small target in the thalamus (the Vim nucleus), disrupting the neural circuit that generates tremor.
One of the strongest-evidence entries in this catalog — a genuinely FDA-approved, sham-controlled-trial-backed procedure.
FDA-approved (PMA supplement, December 2018), incisionless procedure for tremor-dominant Parkinson's disease (unilateral thalamotomy)
A 2025 systematic review of 6 RCTs found no benefit over controls except for static balance, with serious risk-of-bias concerns; earlier meta-analyses found modest, inconsistent gait improvements but no clear benefit on balance or activities of daily living.
Bridge —Standing on a vibrating platform delivers mechanical vibration through the legs, proposed to enhance proprioceptive input and sensorimotor processing relevant to gait and balance in Parkinson's disease.
Multiple meta-analyses since 2020 have reached inconsistent conclusions — an honest example of a plausible mechanism that hasn't held up to consistent replication.
Not FDA-regulated as a PD therapeutic; used as an adjunct physiotherapy modality
Extracorporeal Shockwave Therapy (ESWT) for Myofascial Pain
Device
A 2023 meta-analysis of 27 RCTs found ESWT reduces pain and improves function in myofascial pain syndrome, but a 2022 scoping review found no clear evidence of efficacy specifically for fibromyalgia; a dedicated fibromyalgia RCT found meaningful pain improvement but no change in pain catastrophizing or inflammatory biomarkers.
Bridge —Focused or radial acoustic shockwave pulses are delivered to painful trigger points, proposed to promote neovascularization and modulate inflammatory signaling.
Evidence is meaningfully stronger for myofascial pain syndrome than for fibromyalgia specifically — an important nuance this catalog tries not to blur.
Devices cleared for musculoskeletal pain generally in many jurisdictions; not FDA-approved specifically for fibromyalgia
Cohort data found 69% of chronic wounds healed with a shorter median time to healing than historical controls; a 2020 evidence review concluded results are promising but studies remain underpowered and heterogeneous, cautioning against overstating current certainty.
Bridge —Non-contact ultrasound is delivered through an atomized saline mist to debride wounds and appears to stimulate microcirculation, though the evidence base for the circulatory mechanism is still developing.
Exact 510(k) clearance year not independently re-verified in this pass.
dermaPACE (focused shockwave therapy for diabetic foot ulcers)
Device
Two pooled, multicenter, double-blind, sham-controlled Phase 3 trials (n=336) found significantly greater wound healing at 20 and 24 weeks versus sham, with faster time-to-closure (84 vs. 112 days).
Bridge —High-energy focused acoustic shockwave pulses are applied to the wound bed, proposed to stimulate angiogenesis and wound-healing signaling pathways.
FDA-cleared via the De Novo pathway for diabetic foot ulcers (exact clearance date not independently re-verified in this pass)
Extracorporeal Shockwave Therapy (ESWT) for Tendinopathy
Device
A 2026 meta-analysis of 14 RCTs found radial ESWT was not superior to other electrophysical modalities for pain or function, while a larger 2026 network meta-analysis of 63 RCTs found broad efficacy compared with injections — the evidence genuinely depends on the comparator used.
Bridge —Focused or radial acoustic shockwave pulses target tendon and fascia insertion sites, proposed to promote neovascularization and disrupt calcific deposits.
Included to show how the same modality's evidence rating can shift substantially depending on what it's compared against — not a simple yes/no case.
FDA-cleared (multiple devices; e.g. Storz Duolith SD1, tested in a placebo-controlled Phase 3 trial)
Low-Intensity Pulsed Ultrasound (LIPUS) for Tendon/Ligament Healing
Device
A systematic review of 28 animal and 2 human studies found LIPUS improved collagen organization and healing in animal tendon models, but explicitly found that in human trials, LIPUS treatment of chronic tendinopathies did not improve clinical outcomes — a clear translational failure from animal to human data.
Bridge —Low-intensity pulsed ultrasound delivers mechanical vibration intended to stimulate the same cellular mechanotransduction pathways used for bone healing, applied instead to tendon and ligament tissue — a mechanism that has not translated to human clinical benefit.
A useful honest counterpoint to the bone-healing Exogen entry: the same underlying technology, a real preclinical signal, and a real human-trial failure — included specifically because this catalog doesn't hide negative results.
LIPUS devices are FDA-cleared for bone fracture healing (see the separate Exogen entry); not demonstrated effective for this soft-tissue indication
Whole-Body Vibration Therapy for Knee Osteoarthritis
Device
A 2022 meta-analysis of 14 RCTs (n=559) found whole-body vibration plus strengthening exercise significantly improved pain and function versus exercise alone, with no adverse events reported; a 2025 meta-analysis of 16 RCTs confirmed the pain benefit but found no significant effect on balance or disability.
Bridge —Standing on an oscillating platform delivers mechanical vibration through the legs, proposed to strengthen periarticular muscles and modulate joint pain signaling.
Not FDA-regulated as a therapeutic claim device; investigational adjunct to exercise
A controlled trial comparing percussive massage against cold-water immersion and passive rest after exhausting exercise found neither showed significant recovery benefit over passive rest, only a modest reduction in perceived stiffness; a separate study found real, measurable increases in local blood flow, but that hasn't been shown to translate into a recovery or performance benefit over 24-72 hours.
Bridge —A motorized head delivers rapid percussive vibration to muscle tissue, proposed to increase local blood flow and reduce perceived muscle stiffness after exercise.
The literature here is genuinely sparse (only a handful of controlled studies) relative to how widely marketed these devices are — included as an honest example of a real physiological effect (blood flow) that hasn't been shown to deliver the marketed recovery benefit.
Consumer wellness devices; not FDA-cleared for a therapeutic claim
A 1-year real-world study of over 39,000 treatments found 74.1% of users reported consistent 2-hour pain relief and 26.0% reported pain freedom, with a low device-related adverse-event rate (1.96%); an adolescent real-world study suggested a preventive effect over time.
Bridge —Delivers electrical pulses to the upper arm at parameters designed to trigger conditioned pain modulation, a descending pain-inhibition pathway believed to reduce migraine pain centrally.
An electrical, pulse-frequency-defined device rather than sound or vibration — included under this catalog's broader frequency-defined-intervention umbrella (see About Cymatics). No audible or felt frequency a visitor could sample.
FDA-cleared (2018 acute; expanded to prevention 2021)
An open-label trial (n=132 evaluable) found a mean reduction of 2.75 headache days/month against a pre-specified performance goal of 0.63 days, with a 46% 50%-responder rate versus a 20% goal — both highly significant, though this was an open-label design compared to a performance goal, not a sham-controlled trial.
Bridge —A single magnetic pulse delivered to the occipital cortex is proposed to disrupt cortical spreading depression, the neural event believed to underlie migraine with aura.
FDA-cleared (2014) for acute treatment of migraine with aura
An FDG-PET imaging study found reduced fronto-temporal brain hypometabolism after 3 months of treatment, correlating with reduced attack frequency in patients who used the device as directed.
Bridge —A forehead electrode delivers electrical stimulation to branches of the trigeminal nerve at a chosen pulse-frequency protocol, proposed to modulate the trigeminal pain pathway implicated in migraine.
Exact pulse-frequency parameter not independently confirmed in this pass — omitted rather than guessed.
Repetitive transcranial magnetic stimulation, 10Hz
NeuroStar Advanced Therapy (rTMS, 10Hz)
Device
The pivotal multisite RCT (n=301) found active TMS significantly superior to sham with roughly double the remission rate; however, a separate 13-site sham-controlled RCT in adolescents with treatment-resistant depression found no significant difference between active treatment and sham.
Bridge —Repetitive magnetic pulses at 10 pulses per second are delivered to the left dorsolateral prefrontal cortex, a region implicated in mood regulation.
One of the best-replicated entries in this catalog for adults (~1,900 PubMed articles), but the honest picture is more mixed in adolescents specifically — both results are shown.
Accelerated intermittent theta-burst stimulation (bursts at 50Hz, repeated at 5Hz)
SAINT / Stanford Neuromodulation Therapy (accelerated theta-burst TMS)
Device
An open-label pilot found a 90.5% remission rate; a sham-controlled double-blind RCT (n=29) found a 52.5% mean symptom-severity reduction with active treatment versus 11.1% with sham.
Bridge —fMRI-guided magnetic stimulation delivers rapid bursts (3 pulses at 50Hz, repeated at 5Hz) targeted to a personalized brain circuit connecting the prefrontal cortex to a deeper mood-regulation region, compressing a course of treatment into 5 days instead of the usual 6 weeks.
FDA-cleared (2022), commercialized as the SAINT Neuromodulation System
Transcranial alternating current stimulation, ~10Hz individualized alpha frequency
tACS at Individualized Alpha Frequency
Device
One RCT replicated that a single session of alpha-frequency tACS reduces left frontal alpha power versus sham; a newer, same-lab double-blind RCT found no significant group-level difference in alpha power, though individual reductions still correlated with symptom improvement within the active arm — an unresolved, contested result.
Bridge —Weak alternating electrical current is applied at each person's own individual alpha-band frequency (roughly 10Hz), targeting frontal brain-wave activity linked to reduced approach motivation and anhedonia in depression.
A genuinely open scientific question, included as-is rather than rounded up or down.
A meta-analysis of 15 clinical trials and 11 lab studies (n=849) found a moderate-to-large effect for the bilateral-stimulation component specifically; but a more recent study in PTSD patients specifically found the stimulation reduced subjective distress with no accompanying physiological effect, in contrast to healthy controls.
Bridge —Alternating left-right tactile buzzes or tones are delivered during trauma-memory processing, proposed to engage bilateral brain activation that supports memory reprocessing — though the independent contribution of this component versus the rest of the therapy protocol is unresolved.
The overall EMDR psychotherapy is well-established for PTSD; this entry is specifically about whether the bilateral stimulation component itself (rather than the exposure/cognitive elements of the therapy) has an independent effect — that narrower question remains genuinely contested, especially in clinical PTSD populations versus healthy volunteers.
Sold as a therapist accessory; not independently FDA-regulated as a standalone therapeutic claim
A Cochrane systematic review of 6 RCTs of auditory integration training plus 1 RCT of a related sound therapy (182 participants total) found no evidence that these therapies are effective for autism spectrum disorder; the American Academy of Pediatrics historically advised against their use outside research settings. A separate, more recent regional meta-analysis (13 RCTs, n=976, in Chinese children with ASD) reported significant positive effects — a genuine counter-signal, but from a distinct literature base that hasn't reconciled with the Cochrane concerns about outcome-measure validity.
Bridge —Listening to music that has been electronically filtered and volume-modulated is intended to 'retrain' auditory hypersensitivity believed to contribute to sensory symptoms in autism — a mechanism without confirmed clinical benefit in the best-available controlled trials.
FLAGGED: the highest-quality available evidence (Cochrane) found no benefit, and a leading pediatric professional body has cautioned against use outside research settings. Included specifically to demonstrate the tier/evidence firewall for a sound-based intervention with genuine controversy.
Not FDA-regulated; delivered by private practitioners, typically twenty 30-minute sessions
A completer study (n=115) found a mean 41% reduction in objective snoring and significant improvements in daytime sleepiness and sleep quality; an independent systematic review of 4 studies (n=265) found the devices effective for snoring but described the evidence for improving the apnea-hypopnea index specifically as conflicting.
Bridge —A mouthpiece delivers electrical pulses that migrate through frequencies from 0 up to 20Hz to stimulate and strengthen the tongue muscle during a daytime training session, intended to reduce airway collapse during sleep.
Genuinely FDA-cleared, but strongest for snoring reduction — the core apnea-severity outcome is less consistently supported, an important distinction to keep honest.
FDA De Novo authorized (February 2021) for snoring and mild obstructive sleep apnea