Can 40 Hz Binaural Beats Keep You Focused?
A 2025 study put 40 Hz binaural beats to the test. One setup improved average target detection, but it did not stop attention from fading.
Search for focus audio and you’ll run into 40 Hz pretty quickly. The promise is tempting: put on headphones, press play, and settle into deeper focus.
A 2025 study put a version of that promise to the test, and the answer turned out to be neither a clear yes nor a clear no.
First, a quick definition. Binaural beats happen when headphones play a slightly different tone in each ear, and your brain hears the gap between those two tones as a steady pulse. If the tones are 40 Hz apart, the pulse you hear is a 40 Hz beat. If you’d like to hear one for yourself, our Gamma Waves album is built around a 40 Hz beat.
The Scientific Reports paper A Parametric Investigation of Binaural Beats for Brain Entrainment and Enhancing Sustained Attention, by Anastasiia Melnichuk, Robert K. Cooper Jr., and Larry W. Hawk Jr., tested whether that pulse could help people stay attentive.
First, imagine the task
Picture a stream of four-digit numbers flashing on a screen, where your only job is to press a key whenever the same number appears twice in a row.
It sounds easy until you do it 1,200 times over about 33 minutes, and only 10 percent of the numbers are repeats.
That was the attention test in this study, and it was designed to be long, dull, and hard to sustain. The researchers split it into twelve blocks so they could track two different things:
- How many repeats people caught overall
- How much their performance dropped as time passed
The difference between the overall score and the drop over time is the key to the whole paper.
How they set up the sound
The researchers recruited 80 undergraduates at the University at Buffalo. Twelve didn’t return for the second visit and four were removed for very low task scores, which left a final group of 64 people with an average age of 19.
Each person visited the lab twice, about a week apart, and heard binaural beats during one visit and a plain control tone during the other, in random order.
On top of that, the study varied four parts of the sound:
| Setting | Options |
|---|---|
| Beat speed | 16 Hz or 40 Hz |
| Carrier pitch | 340 Hz or 400 Hz |
| Start time | 10 minutes before the task, or right as it began |
| Background | White noise or no white noise |
The tones played at 70 dB(A), and the white noise, when it was included, played at 60 dB(A).
Each person kept the same beat speed, pitch, start time, and background across both visits, so the only thing that changed between their two visits was whether they heard binaural beats or the control tone. That let the researchers compare like with like.
So, did 40 Hz help?
Yes, in one narrow sense.
People assigned to 40 Hz beats with a 340 Hz carrier caught more targets during their binaural-beat visit than during their control visit. That boost didn’t show up with the 400 Hz carrier, and it didn’t show up in either of the 16 Hz groups.
But here’s the other half of the result: everyone’s performance slipped as the test went on, and the binaural beats didn’t reliably slow that slide.
Think of two people taking the same long quiz. One gets more answers right overall, but both lose steam at about the same rate, so the first person ends up with the better average score without having any more stamina. That’s roughly the split this study found.
The study found one more promising result when white noise was present: on average, the binaural-beat visit produced more correct detections than the control visit. That was a separate comparison, though, so the paper doesn’t show that 40 Hz, a 340 Hz carrier, and white noise add up to one ideal setup.
The higher scores also didn’t come with more careless mistakes. False alarms stayed below 2 percent on average and didn’t differ between visits, and the beats didn’t produce a clear change in the mood measures the researchers used.
What the brain recording showed
The researchers also recorded EEG, which measures electrical activity at the scalp, to see whether brain activity would follow the beat.
It did. Activity increased at 16 Hz during the 16 Hz beat and at 40 Hz during the 40 Hz beat, a pattern called a frequency-following response.
But the EEG and the task scores didn’t line up neatly. White noise weakened the brain’s frequency-following response, especially at 40 Hz, even though the task scores with white noise favored binaural beats.
That mismatch matters, because it means the EEG result doesn’t explain the better average score.
The authors suggest the beats may have helped with a different part of attention, such as noticing the right number or remembering the rule, which could improve the score without improving mental stamina. The study didn’t test those ideas directly, so for now they remain possible explanations.
Why this is not a focus recipe
There are several reasons to keep the conclusion narrow:
- The groups were tiny. The different sound choices created 16 groups with only two to six people in each, which is enough to spot a possible pattern but not enough to name a winning setup.
- The task was narrow. Matching numbers for 33 minutes isn’t the same as writing, studying, coding, or driving.
- The listeners were similar. Most were young college students from a single university.
- There was no silent visit. The study compared beats with a plain tone, so it can’t tell us how either one compares with silence.
- The sound was made for a lab. The tones played at a fixed volume in a sound-treated room, and music or commercial beat tracks may sound very different.
- Some participant counts are unclear. Several analyses used fewer people than the stated final sample, and the paper doesn’t fully explain every difference.
There was also a weak hint that starting the audio ten minutes early might help. That result became harder to trust after a follow-up analysis found the start-time groups were unevenly balanced by race, and in this small sample the pattern was driven by the non-white participants. So it isn’t solid evidence that starting early protects attention.
What the study really gives us
The biggest lesson is that a single number, like 40 Hz, doesn’t describe a whole sound.
The 40 Hz result depended on the carrier pitch, the control sound, the task, and the people listening, and white noise added another wrinkle. Even the meaning of “better attention” changed depending on whether the researchers looked at the average score or the drop over time.
That’s why “40 Hz improves focus” goes further than this study can support. A fairer summary is less catchy but more useful: one 40 Hz setup improved average target detection in a small lab study, while attention still faded at the usual rate.
Our earlier Science Simplified article, Is Noise Always Bad for Creative Thinking?, looks at a different kind of sound and a different kind of thinking. Together, the studies point to the same broad lesson: sound may affect the mind, but the details decide what a result actually means.
If you want to see how this finding plays out in your own work, two companion Field Notes pick it up from here: Use Binaural Beats for a Work Block, Not a Work Marathon and Test a Focus Track Before You Trust It.
This study gives researchers a promising clue, not listeners a proven shortcut.