Tones to leave on

The Resonance Room

Soft, steady tones to sit inside for a while — the frequencies people reach for to settle, sleep or focus. Every tone fades in gently, plays with a warm timbre rather than a raw sine, and can breathe, layer with others, or split into a binaural beat on headphones. A timer fades everything out. The evidence for each is labelled honestly: some of this has small studies behind it, most of it is tradition.

studied  several controlled studies or a meta-analysis point the same way
pilot  one or two small studies — promising, not settled
mixed  evidence goes both ways
tradition  a practice, not a finding — pleasant, harmless at low volume
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Transport
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Binaural beat · headphones 56712
Breathing swell
Pomodoro · work sprints

The room plays through each sprint, dips to a murmur for the rest with a soft chime at every turn, and takes a longer rest after four rounds. With nothing playing it starts the Work preset.

Presets

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Tuning and tone

The two frequencies with the best small-study support, plus the low hums that are easiest on the ear for long stretches.

Sleep sounds

Not frequencies but beds: rain, surf, a stream, wind, a fire, a summer night, a fan, and the two noises. All of it is generated live, so it never loops. Layer one under a low hum, set the timer, and let it carry you off.

The Solfeggio set

Nine tones assigned meanings in the 1970s from a numerological reading of a mediaeval hymn. No controlled evidence apart from 528 Hz — but they sit well together, and the lower ones make good drones.

Leaving it on for hours — the part that actually matters

  1. Volume is the whole game.9 The WHO's safe-listening ceiling is 80 dB for 40 hours a week; a tone you leave on belongs far below that — if someone talking normally beside you is easy to hear over it, you're fine. This page opens at a low room level on purpose.
  2. Low tones wear better than high ones. The ear is most sensitive around 2–5 kHz, and a pure high pitch fatigues faster than a hum. For long sessions stay roughly between 100 and 530 Hz; 852 and 963 Hz are for short sits, softly.
  3. Take the ear off duty. Ten minutes of quiet every hour. The fade-out timer is the easy way to make that happen.
  4. Binaural means headphones.56 The beat only exists inside your head, made from the two ears' slightly different tones. Through speakers it's just a faint wobble. Theta and delta beats have the best evidence for easing anxiety.
  5. Overnight noise is a mixed bag.8 A recent study found pink noise all night cut REM sleep; earplugs protected deep sleep better. Use noise to fall asleep, on the timer, rather than till morning.
  6. Not treatment. Nothing here diagnoses or treats anything. Skip the 40 Hz beat7 if you have epilepsy, and don't use any of this while driving.

The studies, numbered

Every tone above carries small numbers linking here. Where a line says pilot, read the sample size before you read the result.

  1. Calamassi D, Pomponi GP. Explore 2019 — 33 healthy adults, double-blind crossover; the same music at 432 Hz lowered heart rate more than at 440 Hz, with slight drops in blood pressure and breathing rate.
  2. Aravena PC et al. J Appl Oral Sci 2020 — randomised trial in patients having a tooth out; music at 432 Hz reduced dental anxiety and salivary cortisol more than 440 Hz.
  3. Sound interventions at 432 vs 443 Hz in cancer patients, BMC Complement Med Ther 2025 — randomised crossover; cardiovascular parameters shifted differently under the two tunings.
  4. Akimoto K et al. Health 2018 — nine people; after 528 Hz music, salivary cortisol fell and oxytocin rose, with no change after 440 Hz. A single small session: promising, not settled.
  5. Garcia-Argibay M et al. Psychol Res 2019 — meta-analysis of 22 binaural-beat studies; theta and delta beats reduced anxiety with a medium-to-large effect (Hedges' g ≈ 0.69). The strongest evidence on this page.
  6. Binaural beats for perioperative anxiety and pain, systematic review and meta-analysis, 2025 — pooled trials around surgery; anxiety reduced, pain effects smaller.
  7. MIT Picower Institute, 2025 review — 40 Hz light-and-sound stimulation in Alzheimer's research, from mouse models to small human trials. About cognition and brain health, not relaxation; the beat here is a nod to it.
  8. Overnight pink noise and sleep, 2023 — all-night pink noise reduced REM sleep and sleep-dependent insight; earplugs protected deep sleep better. Use noise to fall asleep, on a timer.
  9. WHO — safe listening — the 80 dB / 40 hours-a-week ceiling behind the volume advice above.
  10. The Solfeggio set — where it comes from — nine tones proposed in the 1990s from a numerological reading of a mediaeval hymn; no controlled studies apart from the 528 Hz pilot above. Listed as tradition.
  11. Cousto H. The Cosmic Octave, 1978 — the “planetary” tones, 136.1 Hz among them, derived by octave-shifting astronomical periods into hearing range. A tuning convention, not a finding.
  12. Schumann resonances — the 7.83 Hz resonance of the Earth–ionosphere cavity is real physics; claims about its effect on the body are not supported by controlled studies.
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