sossego — Portuguese for deep, settled calm.
Binaural beats. Listening to two slightly different frequencies through headphones causes the brain to follow the difference between them — a phenomenon called frequency-following response. Meta-analyses report medium-to-large reductions in anxiety (Hedges' g ≈ 0.69 for theta-range protocols; standardised mean difference ≈ −1.38 in perioperative settings). The effect is strongest for situational anxiety; more modest for chronic conditions.
Isochronic tones. A single tone that pulses on and off at the target frequency, producing similar entrainment without requiring headphones — useful on speakers or single earbuds, though the aesthetic is more abrupt than binaural beats.
Music with embedded beats. A 2025 randomized controlled trial from Stanford's Center for Computer Research in Music and Acoustics (Venkatesan et al., n = 308) found that monaural beats embedded in harmonically-matched ambient music significantly reduced anxiety (d = −0.58), while beats alone or pure tones did not. Monaural beats work on any audio output, including phone speakers.
Bilateral motion. An optional layer that oscillates the audio slowly between ears, drawing on a technique from EMDR therapy. fMRI studies show bilateral alternating auditory stimulation modulates amygdala activity and facilitates fear extinction in healthy participants.
Sossego is a wellness tool, not a medical device. It is not a substitute for professional care.
References: Garcia-Argibay et al. 2019; Yan et al. 2025; Boukezzi et al. 2017.