Which binaural beat effects have scientific support
Abstract
Binaural beats are a real auditory phenomenon, but that does not mean each frequency can reliably induce relaxation, sleep, or concentration. The strongest recent evidence concerns anxiety and pain around medical procedures, while findings for stress, cognitive performance, and brainwave entrainment remain inconsistent. Safety is also difficult to assess because adverse effects have rarely been monitored systematically.
Binaural beats are often presented with labels such as “theta for relaxation,” “delta for sleep,” or “beta for concentration.” These claims begin with a genuine auditory phenomenon but add a more demanding proposition: that selecting a particular beat frequency can reliably shift brain activity toward a specific psychological state.
Several separate questions are involved. One concerns whether the binaural beat is perceived. Another concerns whether listening produces a measurable psychological outcome. A third concerns whether any observed effect depends on brain oscillations synchronizing with the presented beat frequency. A measurable effect during one experiment is also different from having a validated protocol for a specific frequency, duration, or application.
Current evidence includes favorable findings in some settings, null findings in others, and several results that run against expected benefits. That pattern calls for a narrower interpretation than either treating binaural beats as a broadly established intervention or dismissing them as incapable of producing measurable effects.
A binaural beat is an auditory phenomenon, not evidence of brainwave entrainment
A binaural beat occurs when tones with slightly different frequencies are presented separately to each ear. If one ear receives a 400 Hz tone and the other a 410 Hz tone, a rhythmic 10 Hz modulation may be perceived even though no separate 10 Hz sound has been played.
That perceived beat is the established starting point. The more uncertain question is whether the frequency difference reliably synchronizes brain activity and whether such synchronization can predictably produce relaxation, attention, sleep, or another mental state.
Ingendoh, Posny, and Heine reviewed 14 studies examining brain oscillatory activity during binaural beat stimulation. Five produced findings compatible with an entrainment hypothesis, eight reported contradictory findings, and one produced mixed results. The studies also differed substantially in stimuli, experimental designs, and EEG analysis methods.
Perceiving a binaural beat or detecting a neural response to sound therefore does not establish brainwave entrainment as a reliable mechanism. The evidence also does not support assuming that a beat labeled delta, theta, alpha, or beta will consistently produce the mental state commonly associated with that frequency band.
The clearest favorable signal is in perioperative anxiety and pain
Recent evidence is particularly relevant in surgical settings. A 2025 systematic review and meta-analysis by Xiong and colleagues included 15 randomized trials examining perioperative anxiety and pain.
The analysis found favorable results for both outcomes compared with control conditions. Benefits were also reported in comparisons with audio that did not contain binaural beats, which helps separate the possible effect of binaural stimulation from the general effect of listening to audio.
The setting matters. Heterogeneity was very high for anxiety, and the included trials differed in procedures and protocols. These findings provide evidence of a favorable signal around medical procedures, but they do not establish binaural beats as a general treatment for anxiety disorders or show that the same effects occur outside perioperative care.
An earlier meta-analysis by Garcia-Argibay, Santed, and Reales combined 22 studies and 35 effect sizes across cognition, anxiety, and pain perception. It reported an overall effect of g=0.45. That value represents the combined set of outcomes included in the meta-analysis. It should not be interpreted as a specific effect size for anxiety.
The 2025 evidence therefore changes the broadest interpretation of the field. It is difficult to describe all applications as having uniformly weak or absent effects, while the perioperative findings still cannot be generalized to anxiety, pain, or well-being in every setting.
Stress and cognitive performance remain much less consistent
For non-clinical stress, Platt and Hammond reviewed 12 randomized or randomized crossover studies. Eight reported at least one favorable outcome, while four found no between-group effects. Differences in protocols, measures, and study designs prevented a strong overall conclusion or the identification of an optimal frequency or exposure pattern.
This variability makes instructions such as “use theta to relax” or “use alpha to reduce stress” difficult to justify. A favorable result under one experimental condition does not establish that the frequency involved is a general-purpose protocol.
Cognitive performance introduces a further complication because effects are not consistently positive. Klichowski and colleagues conducted two home-based studies with a total of 1,000 participants. Under some binaural beat conditions, participants scored lower on fluid-intelligence tasks than at baseline and under other acoustic conditions.
The finding is relevant to claims that binaural beats improve performance while a cognitive task is being completed. It does not demonstrate brain injury, permanent loss of cognitive ability, or clinical cognitive deterioration. It describes poorer test performance under specific experimental conditions.
Taken together, findings for stress and cognition show why fixed functions cannot be assigned confidently to individual beat frequencies. Positive, null, and negative findings coexist, and there is no validated combination of frequency, duration, and context that reliably produces a specified psychological outcome.
An observed psychological effect does not establish the proposed mechanism
Outcomes involving anxiety, pain, stress, or task performance need to be separated from the mechanism proposed to explain them.
A psychological difference between groups can occur without evidence that brain oscillations synchronized with a binaural beat. Conversely, inconsistent evidence for entrainment does not establish that binaural beats are incapable of producing psychological effects through other processes.
The review by Ingendoh and colleagues illustrates this distinction. Electrophysiological studies do not provide a sufficiently consistent pattern to treat brainwave entrainment as an established mechanism. That uncertainty directly affects a common explanatory claim that choosing a beat within a particular EEG frequency band can induce the mental state associated with that band.
Brainwave entrainment is therefore best treated as an unresolved mechanistic hypothesis. Until the relationship becomes more consistent, claims such as “delta for sleep,” “theta for relaxation,” “alpha for stress,” or “beta for concentration” cannot be regarded as validated protocols merely because the selected beat falls within one of those frequency ranges.
Safety data are still too limited to define a specific adverse-effect profile
Existing studies do not support a well-quantified profile of adverse effects specific to binaural beats.
In the systematic review by Platt and Hammond, ten of the twelve included studies did not explicitly report adverse effects. One study stated that no adverse events occurred, while another recorded a mild headache that was also reported in the control condition.
The central limitation is insufficient monitoring. These data do not allow reliable estimates of how often headache, dizziness, irritability, drowsiness, or other symptoms might be caused specifically by binaural stimulation. The absence of reported serious events in small trials also does not establish long-term safety.
The same limitation applies to commonly repeated lists of contraindications. The reviewed evidence does not provide sufficient support for presenting epilepsy, pacemaker use, pregnancy, or being under age 12 as established clinical contraindications to binaural beats. This does not demonstrate that the intervention is specifically safe for those groups. It means the available evidence does not justify presenting those precautions as established clinical contraindications.
The findings from Klichowski and colleagues belong to a different category. A temporary reduction in test performance under particular experimental conditions is relevant when evaluating cognitive-enhancement claims, but it is not equivalent to a serious adverse event or evidence of brain damage.
A separate and well-established risk comes from excessive sound exposure. That risk applies to headphone listening in general rather than to the binaural phenomenon itself. The World Health Organization identifies sound intensity and exposure duration as the main determinants of hearing risk. For adults, it uses 80 dB for up to 40 hours per week as a reference, with safe exposure time declining rapidly as sound level increases.
General safe-listening risk should therefore be distinguished from any hypothesized risk specific to binaural stimulation. Excessive volume can harm hearing when listening to music, podcasts, continuous noise, or binaural beats. It does not demonstrate a unique toxicity of binaural beats.
What the evidence supports today
Binaural beats are a genuine auditory phenomenon, and experimental findings justify continued research into their effects. Among the evidence reviewed here, the clearest favorable signal currently concerns anxiety and pain associated with medical procedures, although substantial heterogeneity limits generalization to other forms of anxiety or pain.
Findings for non-clinical stress and cognitive performance are less consistent. Favorable results coexist with null findings and outcomes that run against claims of cognitive enhancement. Research has also not established an optimal frequency and duration that can reliably produce a specific psychological outcome.
Brainwave entrainment remains an open mechanistic hypothesis. An observed psychological effect does not demonstrate entrainment, while uncertainty about entrainment does not rule out effects in specific contexts.
Safety evidence is less complete still. Few problems have been reported, but adverse events have also been monitored poorly. The available literature therefore supports neither a well-defined binaural-specific risk profile nor a conclusion that the absence of serious signals establishes long-term safety.
The practical boundary is clear: labels that directly connect a frequency with sleep, relaxation, concentration, or a particular brain state go beyond what the current evidence can support. Binaural beats can produce measurable effects in some contexts, but they are not a validated system for predictably selecting mental states through a chosen beat frequency.
References
- Platt J, Hammond L. Is non-clinical, personal use of binaural beats audio an effective stress-management strategy? A systematic review of randomised control trials. Advances in Mental Health. 2025;23(2):258-286. https://doi.org/10.1080/18387357.2024.2374759
- Xiong J, Jiang X, Cai B, Zhao L, Zhang Q, Luo J. Binaural beats for perioperative anxiety and pain: A systematic review and meta-analysis. Complementary Therapies in Medicine. 2025;95:103299. https://doi.org/10.1016/j.ctim.2025.103299
- Ingendoh RM, Posny ES, Heine A. Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity, and the implications for psychological research and intervention. PLOS ONE. 2023;18(5):e0286023. https://doi.org/10.1371/journal.pone.0286023
- Garcia-Argibay M, Santed MA, Reales JM. Efficacy of binaural auditory beats in cognition, anxiety, and pain perception: a meta-analysis. Psychological Research. 2019;83(2):357-372. https://doi.org/10.1007/s00426-018-1066-8
- Klichowski M, Wicher A, Kruszwicka A, Golebiewski R. Reverse effect of home-use binaural beats brain stimulation. Scientific Reports. 2023;13:11079. https://doi.org/10.1038/s41598-023-38313-4
- World Health Organization. Deafness and hearing loss: Safe listening. https://www.who.int/news-room/questions-and-answers/item/deafness-and-hearing-loss-safe-listening
