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Sossego is a Portuguese word with no direct English equivalent — a deep, settled calm. The app exists to help you find it.

Binaural beats reduce situational anxiety with medium-to-large effect (Hedges' g ≈ 0.69 for theta-range protocols; SMD ≈ −1.38 in perioperative RCTs). Effects are strongest for in-the-moment anxiety, more modest for chronic conditions. Garcia-Argibay et al. 2019; Yan et al. 2025.

Sossego is a wellness tool, not a medical device. It is not a substitute for professional care.

Not recommended for individuals with epilepsy, photosensitive seizure disorders, or implanted medical devices (pacemakers, cochlear implants).

This is a wellness tool, not a medical device, and should not replace professional care. If you have concerns about anxiety or a mental health condition, please consult a qualified healthcare professional.

How anxious right now?

Primary evidence — Garcia-Argibay et al. (2019) meta-analysis of 22 studies, 35 effect sizes. Overall: Hedges' g = 0.45 (medium). Anxiety specifically: g = 0.69 (medium-large), strongest in the theta/delta range. Effects appear within a single session and require no prior training. Psychological Research 83(2), 357–372. doi:10.1007/s00426-018-1066-8

Recent RCTs (2022–2025) — Multiple randomised controlled trials in surgical and procedural contexts (bronchoscopy, cataract surgery, GI endoscopy, pterygium surgery) have replicated significant anxiety reduction. A 2025 meta-analysis of 15 surgical RCTs (n > 1,000) found significant reductions in anxiety, heart rate, and systolic blood pressure. Yan et al. 2025.

Frequency choices — Alpha (8–12 Hz): relaxed focus, pre-stress priming — strongest evidence for state anxiety reduction. Theta (4–7 Hz): deeper calm, meditative states. Both ranges are directly supported by the Garcia-Argibay data.

What is contested — The brainwave entrainment mechanism is debated. A 2023 PLOS ONE review found only 5 of 14 studies showed actual EEG frequency-following. The anxiolytic effect is consistently replicated; how exactly the brain produces it is not fully resolved. Isochronic tones have a much thinner evidence base than binaural beats.

Sossego is a wellness tool, not a medical device. Not a substitute for professional care. Not recommended for epilepsy or photosensitive conditions.