Isochronic tones or binaural beats: which suits sleep?

Both isochronic tones and binaural beats put a steady, slow pulse into a track. The aim is the same: give your mind something even and unhurried to settle into. They just get there in different ways, and that difference decides how you can listen to them.

Binaural beats: made in your head

A binaural beat uses two smooth tones, one in each ear, at slightly different pitches. Your brain hears the gap between them as a soft pulse. Nothing in the recording actually pulses. That makes binaural beats very gentle, but it means they only work through headphones. I've written more about them in What are binaural beats?

Isochronic tones: a pulse you can hear

An isochronic tone is a single tone switched on and off at an even rate, say three times a second for a delta track. The pulse is really there in the sound, so you hear it clearly, and it works through speakers as well as headphones.

The trade-off is that it's more noticeable. Some people love the clear rhythm and find it easier to follow. Others find it too insistent to sleep to.

Which suits sleep?

There's no right answer, so here's how I'd choose:

• You sleep with headphones or a sleep headband: start with a binaural beat under rain or ocean. It's the softest option.
• You'd rather use a speaker or a pillow speaker: use isochronic tones, because a binaural beat won't survive the trip through the air.
• You find a clear pulse distracting: binaural, kept low under nature sounds.
• You like having a rhythm to follow as you drift: isochronic, at a low volume.

For sleep, slow speeds are what most people use: delta, below about 4 pulses a second, or theta, around 4 to 8. My Isochronica album is three long isochronic tracks, and Rain on Window pairs rain with a 3 Hz binaural beat.

What the research says is honest but unexciting: the evidence that either method changes your brainwaves is mixed, and there's less of it for isochronic tones than for binaural beats. What they reliably give you is a steady, predictable sound that doesn't grab your attention, and for many people that's enough.

A few cautions

• If you have epilepsy or have ever had a seizure, talk to your doctor before listening to isochronic tones. A clear rhythmic pulse is exactly the kind of thing to check first.
• Never listen while driving or doing anything that needs your full attention.
• Keep the volume low, and if a track gives you a headache or feels uncomfortable, stop.

For relaxation, not a medical treatment. If you're struggling with sleep, please talk to your doctor too.