2 Hz binaural beats and isochronic tones
Last updated June 2026
2 Hz is a deep-delta frequency — two gentle pulses a second, near the slow end of human brainwaves. It maps to the dreamless, restorative stages of sleep, which is why people reach for it to wind down at night and keep a quiet sleep cue running until morning.
What 2 Hz does
At 2 Hz you are well inside the delta band (0.5–4 Hz), the slowest of the five brainwave ranges and the one that dominates deep, non-dreaming sleep. The idea behind playing a 2 Hz beat or pulse is gentle entrainment: a slow, steady rhythm the brain can settle toward as you let go of the day. Because it sits so low, 2 Hz is squarely a sleep frequency — there is nothing alerting about it. It suits the last part of a bedtime routine, when you have stopped scrolling and just want something slow and unobtrusive in the background.
For the broader picture of why slow rhythms line up with deep sleep, the delta waves page covers the science in full.
Binaural or isochronic at 2 Hz?
For an all-night sleep frequency, isochronic tones win on practicality. A 2 Hz binaural beat requires stereo headphones the whole time, which few people can sleep in comfortably. Isochronic tones pulse a single tone on and off, so they entrain through any bedside speaker, phone speaker, or smart speaker with nothing in your ears.
Recommendation for 2 Hz: isochronic on a bedside speaker for hands-off, headphone-free overnight use. If you do an awake wind-down with headphones on, binaural at 2 Hz works fine too — just take them off before you actually drift off.
How to play 2 Hz
- Open the isochronic player. No account, free in the browser.
- Set the pulse to 2 Hz. This is the number that matters — the slow rhythm your brain follows.
- Leave the carrier low. A low carrier (a soft, warm pitch) feels gentler for sleep than a bright one.
- Place a speaker near the bed. Keep the volume low — just audible is enough to entrain.
- Set the sleep timer. A long fade-out means nothing snaps off abruptly if you are still half awake.
Prefer headphones? The binaural player does the same 2 Hz beat split precisely to each ear.
Evidence-aware note: entrainment research is promising but still emerging, and responses vary from person to person. 2 Hz is a sensible deep-sleep starting point, not a guaranteed switch. Entrain is a wellness tool, not a medical device — if you have a sleep disorder or other medical concern, talk to a healthcare professional.
Frequently asked
What is 2 Hz good for?
2 Hz sits deep inside the delta band, the slow rhythm associated with dreamless, restorative sleep. People use it to wind down at the end of the day and to keep a gentle sleep cue running overnight. It is one of the slower frequencies, so it is aimed at sleep rather than focus.
Can I play 2 Hz without headphones overnight?
Yes. Use isochronic tones rather than binaural beats. Binaural beats need stereo headphones, which are uncomfortable to wear in bed, while isochronic tones pulse a single tone that works on any bedside speaker. That makes isochronic the practical choice for all-night use.
Is 2 Hz the best frequency for sleep?
There is no single best number. 2 Hz is a sensible deep-delta default, but some people prefer a slightly higher 3 to 4 Hz to drift off and let the lower frequencies take over naturally. Entrainment research is still emerging, so treat any frequency as a starting point and adjust to what feels restful.