Isochronic tones are the newest technological advancement in the field of brainwave entrainment. Isochronic tones are regular beats of a single tone. In fact, an isochronic tone is a tone that is being turned on and off rapidly at regular intervals, creating sharp and distinctive pulses of sound. This effect called “Amplitude Entrainment” tends to excite the thalamus and causes the brain to generate the same brainwave frequency (“frequency following response”) as the tone. The thalamus, vital structure lying deep within the brain, has multiple important functions: it is involved in sensory and motor signal relay, and the regulation of consciousness and sleep. Therefore, the use of isochronic tones is a very effective way to induce a desired brainwave state.
Beating can also be heard between notes that are near to, but not exactly, a harmonic interval, due to some harmonic of the first note beating with a harmonic of the second note. For example, in the case of perfect fifth, the third harmonic (i.e. second overtone) of the bass note beats with the second harmonic (first overtone) of the other note. As well as with out-of tune notes, this can also happen with some correctly tuned equal temperament intervals, because of the differences between them and the corresponding just intonation intervals: see Harmonic series (music)#Harmonics and tuning.

♥ I've beeen training in self-hypnosis for a while (under supervision and for a reason) and found that the 8-4 Hz beats put me very quickly in a deeply relaxed state. Definitely the thing! With the timer, I can shut them for the real self-hypnosis. I haven't tried the other beat generators yet, but this one works much better than I expected and clearly does the job. In a few words: I'm impressed!

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.

Known as audio-visual brainwave entrainment, or AVE, this method involves the simultaneous flashing of light and audible, rhythmic tones using specialized equipment such as the Mind Machine. Also known as the Dream Machine or psycho-Walkman, this lightweight headset lets you experience a wide selection of audio and visual entrainment tracks while having complete mobility.
The functional role of neural oscillations is still not fully understood;[6] however they have been shown to correlate with emotional responses, motor control, and a number of cognitive functions including information transfer, perception, and memory.[7][8][9] Specifically, neural oscillations, in particular theta activity, are extensively linked to memory function, and coupling between theta and gamma activity is considered to be vital for memory functions, including episodic memory.[10][11][12]