One question people often ask when researching binaural beats is whether or not there are side effects to using the recordings.
And you can't blame anyone for wondering, when you consider that brain entrainment changes brain state – even if it does so positively.
Binaural beats work by sending a specific, different frequency to each ear. The difference between the two frequencies entrains the brain to the desired brain state. But what exactly are these frequencies and do they harm us in any way?
Explaining the Binaural Undertone
The binaural track – the bassy humming sound you hear underneath a recording – is two sine waves combining to activate the frequency response process in the brain. A sine wave is a smooth repetitive oscillation; imagine a long, flat bass note with no melody.
The pattern that creates a sine wave occurs in nature, in ocean waves, sound waves and light waves. A pure sine wave is identified by the human ear as a single frequency with no harmonics, but because a binaural beats track combines two sine waves, there is a subtle, recognisable harmony.
Try this: put on a binaural beats recording and take one earphone off for a second. You should hear a flat sine wave with no harmonics in the remaining ear. Now put the other headphone back on and you will see how the two combine to create a monotonous harmony.
Some people find pure sine waves unpleasant, and naked binaural beats aren't very exciting, to say the least. For this reason, pink noise, natural ambience or meditative style music is used to complement the track.
However, the creator must be careful not to cause interference by layering the binaural track too heavily with sound. Doing so can cause frequency interference, which weakens the effectiveness of the track by interfering with the frequency response process.
The fact is, binaural beats don't require accompanying music to be effective. However, the correct choice of music can encourage the targeted brain state and complement the overall effectiveness of the track.
For example, a Delta recording targeting sleep might use rainfall or other hypnotic natural ambience to create a vibe conducive to deep relaxation. Producers of binaural beats will often use contextual soundscapes that have themselves been proven to induce the brain state being targeted.
Using Binaural Beats Safely
Sine waves are not dangerous, and therefore nor are binaural beats. We hear them every day, in music and in nature. And so, the only side effects that might potentially arise from using binaural beats are those similar to those that would come from an over exposure to music.
For example, if a person who doesn't like dance music listened to two hours of dance music they might develop a headache.
Similarly, some people can end up feeling a little sick when exposed to heavy bass frequencies for a prolonged period. This has been known to occur when a person stands next to a large speaker at a festival/rave for a long period of time.
Reports of side effects from using binaural beats are extremely rare, and there have been no reported dangers documented during controlled studies. You would have to use binaural beats excessively, for perhaps 8 hours in a day, to even trigger a headache.
One thing that should be noted, however, is that increasing the volume of a recording will not necessarily improve the effectiveness of binaural beats, and listening to a 30-minute recording on a very loud setting may make you feel uncomfortable.
You should be in a relaxed state, and therefore the recording should be set on an ear-pleasing medium volume setting whereby the binaural track beat is adequately audible. Using 2-3 recordings (of 30-minutes) per day is an advisable threshold, and will cause no side effects.