Alpha waves (8–13 Hz)

An EEG records voltage changes produced by the brain. Analysing that signal by frequency gives a spectrum, and its slices are named with Greek letters. Alpha is the slice at about 8 to 13 Hz, the middle of the five bands usually described.

These are the ranges Mind Journeys uses. The edges vary between sources, and there is a further complication specific to alpha: the frequency where a person's alpha peaks differs a good deal from one person to the next. A well-known review argues that fixed bands fit individuals poorly and suggests setting the alpha and theta windows for each person around their own peak. So a beat at 8 Hz sits on the border with theta, whichever table you read.

Alpha is the easiest band to see by eye: regular waves at around ten peaks per second, clearest over the back of the head when a person is awake with their eyes closed. Clinical sleep scoring uses it as the marker of relaxed wakefulness, and the light sleep stage N1 is recognised partly by its fading (AASM scoring manual).

Opening the eyes changes the picture. In a study of 28 people at rest, going from eyes closed to eyes open reduced EEG power across the scalp in every band measured, alpha included, and the authors treat the strength of resting alpha as an index of resting arousal.

As with every band, analyses usually measure how much of the signal's power falls in the alpha range rather than judging it by eye. Alpha is always present to some degree; “more alpha” means more of the power, not that the other bands have stopped.

Relaxed, eyes-closed wakefulness

This is the classic alpha state: awake, still, eyes closed, not working hard at anything. It is the reference point the other bands are usually described against.

The edge of sleep

As a person drifts toward sleep, the waking alpha rhythm fades and slower theta activity takes over; that change is part of how stage N1 is scored (AASM scoring manual).

Meditation

A systematic review covering 56 papers and 1,715 participants found that mindfulness practice was most commonly associated with raised alpha and theta power compared with an eyes-closed resting state, while noting that this was not uniformly reported.

Attention and memory tasks

Alpha also changes when people think. The same review of alpha and theta research reports that the extent to which upper alpha desynchronises is positively correlated with long-term memory performance. In that work, less alpha power goes with more engagement, which is one reason “alpha equals relaxed” is too simple.

All of these are observations of the EEG during a state. None is evidence that producing alpha produces the state.

An alpha binaural beat is two steady tones a few hertz apart, one in each ear, with the difference between them in the 8 to 13 Hz range: 200 Hz and 210 Hz give a 10 Hz beat. The beat is produced by the auditory system from two separate signals rather than being present in the air (Oster, 1973), which is why it needs stereo headphones. At 10 Hz it is clearly audible as a fast flutter in the tone.

Calling it an alpha beat describes the sound. Whether brain rhythms then follow it, called entrainment, is the contested part.

Alpha is where most unwinding audio sits: after work, before meditation, or as a resting point on the way down to sleep. A common shape starts higher, in beta, and eases down into a steady alpha hold, often over a calm ambience such as a fire, rain or the sea. Alpha is also the usual starting point for journeys that go further down into theta or delta.

These are descriptions of how people use the audio, not statements about what it does.

Research on binaural beats rarely isolates alpha. A 2019 meta-analysis of 22 studies on memory, attention, anxiety and pain reported that the direction and size of the effects depended on the frequency used, without establishing alpha as the frequency for any outcome.

And the explanation usually attached to these results is unsettled. A 2023 systematic review of fourteen studies measuring brain oscillatory activity during binaural-beat stimulation found five consistent with entrainment, eight contradicting it and one mixed, and advised treating changes attributed to entrainment with caution.

The EEG evidence and the audio evidence are about different things. Alpha being strong in relaxed, eyes-closed rest does not mean an alpha beat produces relaxation, any more than a thermometer reading produces weather.

Bands are a poor fit for individuals. If the right alpha window differs from person to person, a fixed 10 Hz beat is in the middle of one listener's alpha and near the edge of another's, and studies that use one frequency for everyone cannot account for that.

The studies are small and not comparable. Carrier frequency, beat frequency, session length and what is layered underneath all differ between studies, which the 2023 review identifies as a major reason the outcomes disagree (Ingendoh et al., 2023).

Expectation is hard to rule out. Relaxation is usually measured by asking people how they feel, and people who choose relaxing audio expect to feel relaxed.

Four of the built-in journeys settle in alpha, and all are free to play. All need stereo headphones.

Shoreline Drift · 10 minutes · 11 → 8.5 Hz

On a 205 Hz carrier over gentle waves on sand, the beat eases from 11 Hz to 8.5 Hz over three minutes, holds there for four, then rises to 10 Hz for the last three, so it ends awake rather than drowsy.

Evening Unwind · 15 minutes · 14 → 9 Hz

On a 220 Hz carrier beside a fire, the beat comes down from 14 Hz in beta to 9 Hz over nine minutes, then holds at 9 Hz for the last six.

Handpan Settle · 25 minutes · 13 → 8 Hz

On a 210 Hz carrier with slow handpan notes, the beat descends from 13 Hz to 10 Hz over five minutes, holds at 10 Hz for fifteen, then softens to 8 Hz over the last five.

Rain Shelter · 30 minutes · 15 → 8.5 Hz

On a 200 Hz carrier with rain on a car roof, the beat unwinds from 15 Hz to 10 Hz over eight minutes, drifts to 8.5 Hz over the next twelve, and holds there for the last ten.

What are alpha waves?

Alpha is the name EEG research gives to brain activity at roughly 8 to 13 Hz, meaning eight to thirteen cycles per second. It is the rhythm most associated with relaxed wakefulness, and it is easiest to see on an EEG when someone is awake and resting with their eyes closed. Like every band, it is a slice of a frequency analysis, not a switch the brain flips.

What is the alpha frequency range?

Most sources, and Mind Journeys, use 8 to 13 Hz. The edges vary between sources, and a well-known review argues that fixed bands fit people poorly, because each person's peak alpha frequency differs and band edges are better set around that individual peak. So a beat at 8 Hz is on the border with theta whichever table you use.

Why do alpha waves change when you open your eyes?

Opening the eyes reduces EEG power. In a study of 28 people at rest, power fell across the scalp in every band measured, alpha included, when they went from eyes closed to eyes open. That is why alpha is usually described as an eyes-closed resting rhythm, and why its strength is used as a rough index of how aroused or settled someone is at rest.

Are alpha waves the same as being relaxed?

No. Alpha is associated with relaxed wakefulness in the EEG, but an association is not an identity. You can have strong alpha while thinking, and feel relaxed with weaker alpha. The band describes a pattern in the signal; how relaxed someone feels is measured separately, usually by asking them.

Do alpha binaural beats help you relax?

The evidence does not settle it. Meta-analyses of binaural beats report effects that depend on the frequency used and are inconsistent between studies, and a 2023 review found more EEG studies contradicting the idea that brain rhythms follow the beat than supporting it. People use alpha audio as a background for unwinding, not because research has shown it relaxes anyone.

• how theta waves are definedThe drowsy edge between waking and sleep, and the band most meditation journeys sit in.
• what beta waves areThe band of alert, active thinking, and the range most focus journeys climb into.
• what a binaural beat is and how one is madeThe pillar explainer: the two tones, the perceived beat, and where the evidence currently stands.
• why binaural beats need stereo headphonesWhy speakers cancel the effect, what to listen on, and how loud is too loud.

Browse all guides — the binaural beat and brainwave explainers, grouped by topic.

1. Berry, R. B., et al. The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications. American Academy of Sleep Medicine. https://aasm.org/clinical-resources/scoring-manual/
2. Klimesch, W. (1999). EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis. Brain Research Reviews, 29(2–3), 169–195. https://doi.org/10.1016/S0165-0173(98)00056-3
3. Barry, R. J., Clarke, A. R., Johnstone, S. J., et al. (2007). EEG differences between eyes-closed and eyes-open resting conditions. Clinical Neurophysiology, 118(12), 2765–2773. https://doi.org/10.1016/j.clinph.2007.07.028
4. Lomas, T., Ivtzan, I., & Fu, C. H. Y. (2015). A systematic review of the neurophysiology of mindfulness on EEG oscillations. Neuroscience & Biobehavioral Reviews, 57, 401–410. https://doi.org/10.1016/j.neubiorev.2015.09.018
5. Oster, G. (1973). Auditory beats in the brain. Scientific American, 229(4), 94–102. https://doi.org/10.1038/scientificamerican1073-94
6. Garcia-Argibay, M., Santed, M. A., & Reales, J. M. (2019). Efficacy of binaural auditory beats in cognition, anxiety, and pain perception: a meta-analysis. Psychological Research, 83(2), 357–372. https://doi.org/10.1007/s00426-018-1066-8
7. Ingendoh, R. M., Posny, E. S., & Heine, A. (2023). 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, 18(5), e0286023. https://doi.org/10.1371/journal.pone.0286023