Brainwaves and Music: What Research Shows About Binaural Beats, Sleep Sounds and 40 Hz, and What It Does Not

"Beta for focus, alpha for relaxation, delta for deep sleep" is a popular way to choose music. This page looks at what brainwaves are, what research shows about sound and brain activity, and where the popular claims go further than the evidence.

Every study below was checked against its original abstract, and each one is linked (checked November 2026).

The short answer

What is known: brainwaves are rhythms in the electrical activity of the brain, recorded with EEG, and they change with sleep and alertness. Precisely timed sounds during deep sleep strengthened the slow brain rhythm of deep sleep in a laboratory study.
What is not known: that playing a particular tone or frequency (for example 174 Hz for delta sleep or 528 Hz for alpha) puts the brain into a matching state. For binaural beats, studies testing whether the brain actually follows the beat gave inconsistent results.
A practical approach: choose sound by what you are doing and how it feels to you, keep the volume low, and treat any effect as your own observation (section 4).

1. What Brainwaves Are

Brainwaves are the combined electrical rhythms of large groups of nerve cells, recorded with electrodes on the scalp (EEG). They are usually grouped by speed:

Band	Speed	Usually seen during
Delta	about 0.5 to 4 Hz	Deep sleep
Theta	about 4 to 8 Hz	Drowsiness, light sleep, some kinds of meditation
Alpha	about 8 to 12 Hz	Relaxed wakefulness, often with the eyes closed
Beta	about 12 to 30 Hz	Active thinking and alertness
Gamma	above about 30 Hz	Many kinds of active processing

The boundaries differ a little between textbooks, and every band is present to some degree at any time. A band is a description of brain activity, not a switch that a sound can flip.

2. Why a Tone Number Is Not a Brainwave

A common claim pairs Solfeggio tones with brainwave bands: 174 Hz for delta sleep, 528 Hz for alpha, 741 Hz for beta. An earlier version of this page made those pairings. We removed them because no study supports them.

A 174 Hz tone vibrates 174 times per second. Delta waves cycle 0.5 to 4 times per second. The hearing system does follow the rhythm of a sound: this is called the frequency-following response, and it has been traced to the auditory pathway and the auditory cortex (Coffey et al. 2016). That is how we hear pitch. It is not the same as the whole brain moving into a sleep or meditation state.

3. What Research Shows About Sound and Brain Activity

Study	What was done	What was found	Keep in mind
Ngo et al. 2013 Neuron	Short sounds played to sleeping people, timed to the peaks of their own slow brain waves	The slow rhythm of deep sleep grew stronger and memory consolidation improved. Sounds played out of time did nothing	Needs live EEG to time each sound. A continuous noise track is not the same thing
Garcia-Argibay et al. 2019 meta-analysis	22 studies of binaural beats on memory, attention, anxiety and pain	An overall medium-sized effect	Study quality and methods vary widely
Basu and Banerjee 2023 meta-analysis	15 studies of binaural beats on memory and attention	A medium-sized effect	The authors report conflicting results between studies
Ingendoh et al. 2023 systematic review	14 studies testing whether brainwaves actually follow binaural beats	Five supported it, eight did not, one was mixed	The basic mechanism has not been established
Jespersen et al. 2022 Cochrane review	13 trials (1,007 people) of listening to music for insomnia	Self-rated sleep quality probably improved	Objectively measured sleep may not change
Martorell et al. 2019; Cimenser et al. 2021; Chan et al. 2025	40 Hz sound (and light) stimulation in mice with Alzheimer-like changes, then small trials with special devices in people with Alzheimer disease	Changes in the mice; signs worth studying further in 22 and 5 patients	Not binaural beats, not a treatment, and not evidence for healthy people. Talk to a doctor about any memory concern

What this adds up to: sound can interact with brain rhythms under carefully controlled conditions. That is a long way from "play this frequency to enter that state." For everyday listening, the honest guide is how the sound feels to you.

4. Choosing Sound by What You Are Doing

Falling asleep

Quiet music or steady sound you find pleasant, at a low volume
A sleep timer, so that sound later in the night does not wake you
Our step-by-step guide: The 30 Minutes Before Sleep

Focus

Many people prefer steady sound without lyrics while working. Try a few kinds and compare how much you get done
If sound distracts you, silence is a fine choice

Relaxing

Slow, soft music or nature sound
Sitting or lying comfortably, with the eyes closed if you like

Binaural beats

If you want to try binaural beats, you need headphones, and the research summary above applies. Our guide explains how they work and how to try them: What Are Binaural Beats?.

5. Safety

Keep the volume low. If your ears ring or feel full, stop and rest them
If you have epilepsy, talk to your doctor before using any flickering light or rhythmic stimulation device
Sound is not a substitute for medical care. If sleep problems, low mood or memory concerns last for weeks, see a doctor

6. Frequently Asked Questions

Q1. Do binaural beats change brainwaves? A. Studies that measured this directly gave inconsistent results: five supported it and eight did not (Ingendoh et al. 2023).

Q2. Does a 174 Hz tone help deep sleep? A. We found no study testing this. A 174 Hz tone is a pitch you hear, not a 0.5 to 4 Hz brain rhythm (section 2).

Q3. Is pink noise good for deep sleep? A. In the laboratory, short sounds timed exactly to the slow waves of deep sleep strengthened them (Ngo et al. 2013). Continuous noise played from a speaker was not what was tested.

Q4. What about 40 Hz and Alzheimer disease? A. This is being studied with special devices, after results in mice. It is not an established treatment, and it is not the same as listening to 40 Hz binaural beats. Please talk to a doctor about memory concerns.

Q5. Are headphones required? A. Only for binaural beats, which depend on a different tone reaching each ear. Other music works on speakers.

Q6. Is it safe for children or during pregnancy? A. Ordinary music at a low volume is part of daily life. We do not recommend any stimulation device without a doctor’s advice.

Q7. Can I measure my own brainwaves? A. Consumer EEG headbands exist, but their readings are much less detailed than laboratory EEG. Treat them as a rough guide.

Q8. How long until I notice something? A. There is no research-based timeline. If you try a sound for sleep or focus, note how you feel for a week or two and compare with nights or days without it.

7. Conclusion

Brainwaves are real and they change with sleep and alertness. The idea that a particular tone number switches the brain into a matching state is not supported by research. Choose sound for how it feels and how it fits what you are doing, keep it quiet, and trust your own notes more than any promise.

10 November 2026: We rewrote this page using studies we could check against the original sources. We removed the pairing of Solfeggio tones with brainwave bands, the daily brainwave schedule, and several claims about sleep, insomnia, trauma and gamma waves that we could not support.

References

This article does not guarantee any medical or health benefit and is not a substitute for professional medical care. If you have any health concerns, please consult a physician or other qualified professional.