If you want the most results in the least amount of time, a well balanced approach is to listen to IQ Increase and Beta Relaxed Focus once or twice per day, and then use one of the 30 or 60 minute meditation tracks once during the day and again as you are going to sleep. That means a maximum of FOUR entrainment sessions per day. Trust me, that is a LOT of entrainment for your brain.
Synchronized brain waves have long been associated with meditative and hypnogogic states, and audio with embedded binaural beats has the ability to induce and improve such states of consciousness. The reason for this is physiological. Each ear is "hardwired" (so to speak) to both hemispheres of the brain (Rosenzweig, 1961). Each hemisphere has its own olivary nucleus (sound-processing center) which receives signals from each ear. In keeping with this physiological structure, when a binaural beat is perceived there are actually two standing waves of equal amplitude and frequency present, one in each hemisphere. So, there are two separate standing waves entraining portions of each hemisphere to the same frequency. The binaural beats appear to contribute to the hemispheric synchronization evidenced in meditative and hypnogogic states of consciousness. Brain function is also enhanced through the increase of cross-collosal communication between the left and right hemispheres of the brain.
In other words, you give the well a little taste of what it is you want from it, and then the well responds by delivering more of the same back to you. In the case of the water well, you pour a small amount of water down into the pump. This is known as “priming” the pump. Until you do this the pump does not produce the water you’re looking for. Once you prime the pump it sets up the conditions in which that pump can do its job and the water begins to flow.
Brainwave entrainment also happens with the use of pulsating light, and visual and auditory stimuli are sometimes combined for additional effect and visual stimuli is used alone. Using brainwave entrainment techniques is safe for almost everyone, the exception being pregnant women and people who have seizure disorders who should check with their physician before using these methods.

Theta waves also have been observed in moments when a person recalls information from the past, and this may be what links them also to improvement in learning ability. We also experience theta waves when we go into automatic pilot mode, such as when doing a repetitive task like driving a familiar route where the mind become disconnected while you still drive safely toward your destination.
If you’re operating in Alpha mode, you’ll feel very present and in the moment. You might be somewhat reactive to the world around you, but you’ll feel like you have time to process what’s going on rather than just react on instinct. This is a wonderful state to achieve when meditating or doing something that requires coordination, focus and learning.
“One of the best ways to explain how brainwave entrainment works is by observing the effect of a tuning fork on a guitar string,” says Naik. “Hit a tuning fork tuned to a particular sound frequency, such as the note C, and hold it close to the strings of a guitar. You will notice that the C string on the guitar starts to vibrate because it has entrained on to the same frequency of the tuning fork.”
, that is, the average of the two frequencies. It can be noted that every second burst in the modulation pattern is inverted. Each peak is replaced by a trough and vice versa. However, because the human ear is not sensitive to the phase of a sound, only its amplitude or intensity, only the magnitude of the envelope is heard. Therefore, subjectively, the frequency of the envelope seems to have twice the frequency of the modulating cosine, which means the audible beat frequency is:[5]

A 2008 study at Hofstra University played two different binaural beats and a control sound (a babbling brook) to patients with high blood pressure. There was no difference between the groups. In one small study from Japan that was published in the Journal of Neurophysiology in 2006, they played various binaural beats to nine subjects, and observed the resulting EEGs. They found great variability in the results. Their conclusion was that listening to binaural beats can produce activity on the human cerebral cortex, however the cause was more likely a conscious auditory reaction and was not correlated to the frequency of the binaural beat. However, a 2005 study published in Clinical Neurophysiology found that they were able to induce a desired frequency in the EEG matching the phantom beat frequency encoded in a binaural beat, however this was with a single subject and was neither blinded nor controlled.

Binaural Beats or “binaural tones” are created by playing slightly different frequencies separately into each ear. The difference between the two frequencies stimulates a response in the brain which correlates with this frequency difference. For example, if we present a 100 Hz tone to the left ear and a 105 Hz tone to the right ear, a frequency of 5 Hz is stimulated. This is what is known as the “frequency following response”.
The activity of neurons generate electric currents; and the synchronous action of neural ensembles in the cerebral cortex, comprising large numbers of neurons, produce macroscopic oscillations. These phenomena can be monitored and graphically documented by an electroencephalogram (EEG). The electroencephalographic representations of those oscillations are typically denoted by the term 'brainwaves' in common parlance.[4][5]