Brainwave Entrainment
Brainwave entrainment describes a measured frequency-following response in some study conditions, where neural activity may align with properties of a repeated stimulus. This is achieved through the presentation of two different tones to each ear — binaural beats.
"Auditory beat stimulation... has been shown to affect cognition and mood states, modulating specific brainwave frequencies."Chaieb et al. (2015), Frontiers in Psychiatry
Research & Efficacy
Gamma (40Hz) & Focus
A 2025 study investigated whether 40 Hz binaural stimulation affected attention and gamma-band activity under its experimental conditions. It does not establish a general medical benefit.
Scientific Reports 2025 — read studyDelta (0.5-4Hz) & Sleep
Delta activity is associated with deep NREM sleep. A 2022 review found heterogeneous binaural-beat protocols and outcomes, so results should not be generalized to every listener.
Systematic review 2022 — read sourcePink Noise
Pink-noise power decreases as frequency rises. One small study reported changes in sleep stability during exposure; this is not proof that every pink-noise session improves sleep.
Zhou et al. 2012 — read study