The Science of Binaural Beats & Brainwave Entrainment

Trying to decide which brainwave entrainment CD program to work with? In today's crowded market, the choice is bewildering. Here's some advice -- listen to the music! That way, you can be sure that you've found a program you can easily work with.

But what should you listen for? And how does the music work?

Incorporating entrainment itself, meditation music is a form of cheating. It's a method for deliberately switching on new brain states that lets you bypass years of disciplined meditation.

The frequency following response on which entrainment CDs depend is a simple reflex that can be triggered by the bleeps and bloops of a computer soundcard, provided that those sounds are in the correct rhythms. But no-one wants to spend 30 minutes or more a day listening to a computer.

Relaxation CDs have always mixed a variety of sonic ingredients to provide a satisfying musical experience, and modern meditation music CDs build on that. In this article, we'll look at the components that go into great-sounding meditation music.

First, there's the sound of the developer's chosen entrainment mechanism. When you look at different meditation music programs, you'll come across buzzwords like 'monaural', 'binaural' and 'isochronic'. These are too complex to cover in this short article, so you'll have to read up on them elsewhere on this site. But we should mention the 'Oster curve', named for the researcher who laid the foundations of modern brain entrainment.

Meditation music carries its entrainment signals encoded in musical tones, and Oster recognized that different tones are appropriate for different kinds of entrainment. For instance, brainwave entrainment music focused on the theta wave states associated with deep meditation will tend to use tones in the 160-210hz range. These give it a characteristic sound -- around the same pitch as the 'D' string on a guitar.

Even more importantly, modern brainwave entrainment systems -- such as the Brain Evolution System -- use specific techniques to actually embed entrainment into the music itself, by slightly varying the frequency to produce the desired effect. This may make the music (or ambient noise) sound a little "wobbly" to the listener -- whereas in fact the entrainment is disguised under the audio, in order to produce the desired effect.

Most commercial meditation music these days sounds a little like traditional relaxation CDs. When you listen, you often don't register the entrainment tones. Instead, you'll be conscious of hearing rainfall, wind or the sea -- or the pure hiss of white noise. These so-called ambient sounds serve more than one purpose. They're soothing and pleasant in themselves, and they also distract attention from the more insistent brainwave entrainment tones.

The same is true of the drone sounds that you hear on many recordings. Drones are a feature of musical systems all over the world. When used for brain entrainment meditation, they may take the form of vocal chants, or sustained instrumental notes. These give a static or slowly changing harmonic basis to the faster-moving elements, providing continuity and a sense of groundedness.

In modern systems like the Brain Evolution System, these additional sounds may themselves be individually manipulated to produce complex and multilayered entrainment effects.

Many entrainment CDs feature melodies, usually slow and rhythmically free. Some also include 'guided meditation' voiceovers intended to orientate the listener within their brain entrainment meditation session by the use of word-pictures describing an imaginary journey. Opinions are divided about both these extras, with criticism of guided meditation being particularly fierce. In fact, many developers now indicate clearly which of their disks include guided meditation -- if you're averse, choose an 'ambient soundtrack' disk instead!

However the entrainment CD you choose is composed -- and whatever its intended purpose -- make sure that you enjoy listening to it. You'll be spending a lot of time with your chosen program, and it's important that you're comfortable with it.