Binaural beats are created by introducing two tones differing frequency into each ear. If we play one tone at 100Hz in one ear and another tone at 114Hz in the other ear, the brain will detect a phase difference between the two wavelengths of each signal or tone. In nature, detecting the phase difference is important for directional information.
A binaural beat is created when the signals integrate. Your brain will perceive a beat of 14Hz. Depending on the frequency of the phase difference it can sound like a wave or beat. If the frequency is low, it will sound more like a wave. If the frequency is higher is can sound like a very fast beat.
Stereo headphones must be used in order to make use of this technology. If you were to use speakers, the tones would mix in the air and not give you the desired effect. It can produce a monoraul beat, which can be used for brain wave entrainment (bwe). However, if the track was created for binaural beats, it should be used as such.
When listening to binaural beats, there may be a warbling sound initially until your brain adjusts. Also, having a hearing loss in one ear will not reduce the effectiveness of binaural beats because they maintain their intensity regardless of amplitude. Alternatively, masking the binaural beats with noise does not decrease their effectiveness, in fact, it has been shown to improve the entrainment process and have a more soothing effect.
Using binaural beats as a means for bwe is debatable. Binaurals can be used to produce beats from 0.235Hz up to 26.25Hz, after which the wavelength are too long. Dr. Gerald Oster did a lot of research when it comes to binaural beats. He concluded that they would be insufficient for bwe since the depth of each beat is slightly above a whisper.
There are many companies that use binaural beats as the baseline in their products. These companies range from The Monroe Institute (Hemi-Sync), Centerpointe (Holosync), and I-Doser. They mix their beats with ambiance, music, noise and sometimes guided instructions.
There are other methods which are more efficient like isochronic tones, monoraul beats, low-pass filter modulation, cross-feed modulation, pitch modulation and auto pan modulation. Each type of technology has its own limitations and methods. We use a combination of these methods to produce the best results.