Which binaural beat settings entrain the brain, and do they help attention?

Studies of binaural beats and attention contradict each other, and Melnichuk, Cooper and Hawk suspected the reason is that everyone uses different settings. So they varied the settings on purpose. Eighty students were randomized across sixteen combinations of beat frequency (beta or gamma), carrier tone (340 or 400 Hz), whether the beats started before or with the task, and whether white noise played underneath. Each person did a sustained-attention task on two visits, once with beats and once with control audio, while EEG checked whether the brain actually followed the beat.

The EEG said yes: entrainment occurred, though how strongly depended on the settings and on the background noise. Attention was a more mixed story. One combination, gamma beats over a low carrier with white noise, improved overall task performance. No combination stopped the usual decline in vigilance over time, which is the thing “sustained attention” is supposed to mean.

The authors read this as binaural beats influencing some aspect of cognition other than sustained focus, and call for work on how the parameters interact.

Limitations. Five people per factorial cell is thin for detecting interactions, the attention effect appeared in one of sixteen combinations, and the vigilance result was null. The entrainment finding is solid; the cognitive benefit is partial, which is why we grade the evidence mixed.