[…] We are fortunate in this day and age to have technology available to us that effortlessly leads the brain into deep meditation, through a scientific process called the ”frequency following response”.  This amazing technology, most commonly called brainwave entrainment, substantially enhances the meditative process, and allows people in their very first session to reach brainwave states that would otherwise take several years to reach through traditional meditation techniques.  This means that you can start reaping the powerful benefits of meditation quickly, and without having to exercise your “discipline muscle” at all!  If you are interested- learn more about brainwave entrainment. […]
Isochronic tones work just the same in delta as they do in alpha, theta and beta and they are widely used in the brainwave entrainment community to help people sleep. Like you, I’ve also seen some websites saying they don’t work in delta, but it’s a bit like the game of Chinese Whispers, where someone makes a comment and then after it gets passed around and shared a lot the message gets distorted and appears to be a fact. I don’t know of any scientific reason why they wouldn’t work in delta. I remember some people talking about this on a brainwave entrainment forum many years ago. They were saying they found isochronic tones a bit too abrupt for using to help them sleep and they preferred binaural beats, as they thought they were a more soothing sound. That was just a personal preference shared by a couple of prominent forum members at the time and some people then took that as a fact for everyone. That’s where I think that belief originated from.
In BrainAscend, each brainwave frequency is stimulated for several minutes before progressing deeper.  Much like a staircase type of progression, but with small and smooth steps. This is the most effetive way and also stimulates the release of "feel good" brain chemicals such as serotonin which makes you feel happy. This chart shows the range that each level covers as well as the whole program.
In the past, the most common method of inducing specific brainwave states was through the use of binaural beats. One specific beat was played in one ear (through stereo headphones) and a different beat was played through the other. What the brain would naturally do in hearing these variated beats was create its own beat from the combination of the two (ie if a beat at 100 Hz was played in one ear, and a beat of 110 Hz was played in the other, the brain would resonate at 10Hz). Aside from this directing the brain into a specific state, it also causes the two hemispheres of the brain to synchronize, promoting whole brain functioning. More recently, other methods have been discovered for inducing specific brainwave states, such as isochronic tones, and monaural beats, but the bottom line is that
Thank you for the info. I must add that the Yoga Nidra state is the state in which a person can be in Delta but fully conscious. I did experience this state accidentally 3x in 2yrs after discovering Swami Rama’s teachings about the state&1 of the techniques for it(only 4 seems to exist & are practiced in monasteries at the time,according to him. He was the yogi who 1st demonstrated the 4 states,fully aware of himself & his surroundings, under lab conditions).
Cvetkovic D, Simpson D, Cosic I (2006). “Influence of sinusoidally modulated visual stimuli at extremely low frequency range on the human EEG activity“. Conference proceedings : … Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 1: 1311 – 4. doi:10.1109
Entrainment is a term originally derived from complex systems theory, and denotes the way that two or more independent, autonomous oscillators with differing rhythms or frequencies, when situated in a context and at a proximity where they can interact for long enough, influence each other mutually, to a degree dependent on coupling force, such that they adjust until both oscillate with the same frequency. Examples include the mechanical entrainment or cyclic synchronization of two electric clothes dryers placed in close proximity, and the biological entrainment evident in the synchronized illumination of fireflies.[13]