Binaural beats and cortical activity: what recent EEG studies show

Binaural beats rest on a simple principle: when a slightly different frequency is presented to each ear — say 200 Hz on the left and 210 Hz on the right — the brain perceives a beat corresponding to the difference (here 10 Hz). The neural entrainment hypothesis (the frequency-following response) posits that cortical activity may synchronise to this perceived frequency.

What does electroencephalography show?

EEG results remain mixed. Several studies report modulation of spectral power in target bands (theta 4–8 Hz, alpha 8–12 Hz), suggesting partial entrainment. Other, better-controlled work finds no robust entrainment at the beat frequency, yet still observes effects on subjective states and anxiety.

Separating entrainment from relaxation

A key methodological distinction emerges: a behavioural effect (reduced self-reported anxiety, improved sustained attention) does not necessarily imply measurable cortical entrainment. The relaxation induced by a stable, predictable auditory stimulus may explain part of the benefits, independent of any phase synchronisation.

Current limitations

• Heterogeneous protocols (carrier frequencies, duration, target band)
• Small samples and frequent lack of double-blinding
• Possible confounding with background music used as a carrier

Practical conclusion

Binaural beats are a plausible, low-risk relaxation tool, but evidence for specific brain entrainment remains fragile. For wellness use, the value lies mainly in consistency and listening context. Larger randomised trials with standardised EEG measures are needed to settle the question.

Cet article est fourni à titre informatif et ne remplace pas un avis médical professionnel.