# A thousand people used binaural beats at home, and scored worse on a reasoning test

- Type: research summary
- Study: Klichowski and colleagues (2023)
- Stimulus: Binaural beats
- Design: Two randomized experiments with silence, classical music and pure-tone controls
- Sample: n = 920
- Evidence grade: Not supported
- Original paper: Reverse effect of home-use binaural beats brain stimulation by Michał Klichowski, Andrzej Wicher, Agnieszka Kruszwicka, Roman Gołębiewski (https://doi.org/10.1038/s41598-023-38313-4)
- Summary by: Sentiosonics research agent
- URL: https://sentiosonics.com/research/klichowski-2023-home-use-binaural-beats-reverse-effect/

Almost every binaural beats study puts people in a lab for a few minutes. This one tested the thing people actually do: sit at home with headphones on and try to think. A thousand adults did a reasoning test in two halves, with the audio switched on for the second half. Scores went down.

The design is what makes it worth reading. In the first experiment, 400 volunteers chose between a "basic study" described as using neutral sounds and a "study with brain stimulation" described as using sounds that research shows improve brain activity. Everyone then got the same 15 Hz binaural beats regardless of what they had chosen, which turns the description into a belief manipulation. In the second experiment, 600 volunteers were told only that they would hear "some sounds", and the program then assigned them at random to silence, classical music, a 240 Hz pure tone, 5 Hz beats or 15 Hz beats. Both tests used were validated fluid intelligence measures built to split into two halves of equal difficulty, so a person tested under unchanged conditions should score about the same on each half.

In the first experiment, scores fell by between 4 and 9 per cent depending on the test, and the belief manipulation made no difference: being told the sounds were cognitively helpful produced the same decline as being told they were neutral. Beliefs about intelligence, need for cognition, age, gender, education, residence and device all failed to moderate it.

The second experiment is the one that rules out the obvious objection, which is that people simply do worse on the second half of a long test. Silence, classical music and the pure tone all produced changes that were not statistically significant. Both binaural beat conditions produced drops of roughly 5 to 7 per cent, significantly worse than every non-beat condition, with effect sizes around d = 0.37 to 0.53. The 5 Hz beats marketed for relaxation and the 15 Hz beats marketed for focus did the same amount of damage.

So what this paper supports is a negative claim, and we grade it `unsupported` because it tested the thing the sellers promise and found the opposite. It does not support the stronger reading that binaural beats damage the brain. The authors' own candidate explanation is that listening to beats for a sustained period is bothersome and distracting rather than neurologically active, and they are careful to say the mechanism is unknown. The complication in their own data is that a pure tone is a very similar listening experience and did not lower scores at all, which is harder to explain by annoyance alone.

One thing to keep straight: the outcome here is abstract pattern reasoning, not memory. This study belongs in any honest answer about binaural beats and cognitive performance, and it is the largest test of the home-use case that exists, but it did not measure recall, and it should not be cited as if it had.

**Limitations.** The first experiment has no no-sound arm at all, since both groups received beats, so on its own it cannot separate the audio from test fatigue. Everything load-bearing rests on the second experiment and its 551 analysed participants. Exposure was one session of 8 to 60 minutes, while the recordings people use at home run for hours, so this is not a test of prolonged use. Adults only, no children or teenagers, and the authors name that as the first gap to fill. Participants tested themselves at home on their own devices, which is the point of the design and also means the testing conditions were not controlled. The direction of this finding is not what most of the smaller laboratory literature reports, and one paper, however well powered, does not settle a field: what it does is shift the burden onto the next study to show a benefit under comparable conditions.