But again, when it comes to subjective experience, and mental evolution, I would have to caution you to take what anyone says with a grain of salt. Obviously people want to sell these products. There are some good ones out there and there are some bad ones out there. There are differences in quality, as well as differences in intent with how the audios are to be used.
Theta brainwaves are the next level down from alpha, at a range of 4Hz-8Hz. These brainwaves commonly occur just before sleep, or in the lighter stages of sleep. They also occur while you are day dreaming, or when you experience a strong emotion. It is not so common for an adult to produce prolonged theta brainwaves unless they are an experienced meditator, or perhaps deeply involved in an intuitive art such as music or painting. A dominant theta brainwave state is one of deep relaxation (deeper than alpha) and natural healing. In prolonged dominant theta states, the brain’s sodium/potassium ratio resets and balances itself, curing mental fatigue, and improving the brain cells ability to transport and exchange neuro-chemicals. Without the means of deep meditation, or brainwave entrainment technology, this benefit would only otherwise come from sleeping or napping.Theta is known as the one of the best states for communication with the subconscious mind.
The good news is there are loads of guided meditations which will not only take you into theta brain waves, but will make you feel good about yourself at the unconscious level too. These are some of my favourite types of brainwave entrainment - and you can get them on topics such as money, confidence, creativity, success, relationships, weight loss, smoking and more.
Because of the way they are created, there may be a positive benefit from listening to binaural beats without considering the brainwave entrainment aspect, but I haven’t seen any research on that. I first discovered brainwave entrainment through binaural beats about 10 years ago now, but they didn’t do anything for me. So I’ve never been a regular user of them. I believe isochronic tones are a more effective way to produce hemispheric synchronisation because they produce a much stronger response in the brain
However, those with ASD are sometimes also diagnosed with ADHD. Although they are different conditions, some of the symptoms can be intertwined, which it appears may be the case with your grandson. So I would start by trying out my tracks for ADHD. You can try those out for free on my YouTube channel and I’ve put them together in a playlist here: https://www.youtube.com/watch?v=RKao2oZZPnw&list=PLveg0IEcZWN5iVmMduR9UjLzX_YgCetds. The corresponding MP3 versions for those tracks can be found on my site here: https://www.mindamend.com/intelligence-and-brain-power/. I hope that helps.
But especially at this point, I’m on a mission to get as many people using Holosync® as I possibly can—my current goal is 100 million Holosync® users. Because we already have so many people using it, the economy of scale allows me to offer it to you for MUCH less than what my accountant suggested: just $179 if you’d like Awakening PrologueTM on CDs… or $159 if you want the downloadable MP3 version…
Subsequently, the term 'entrainment' has been used to describe a shared tendency of many physical and biological systems to synchronize their periodicity and rhythm through interaction. This tendency has been identified as specifically pertinent to the study of sound and music generally, and acoustic rhythms specifically. The most ubiquitous and familiar examples of neuromotor entrainment to acoustic stimuli is observable in spontaneous foot or finger tapping to the rhythmic beat of a song.