In the 1980s, a researcher in Japan, Tsuyoshi Inouye described how light stimulation creates synchronization of brain hemispheres. Since then, other researchers have detailed the positive effects of hemispheric synchronization including a 1984 study by researcher Dr. Gene W. Brockopp stating that hemispheric synchronization resulted in improved intellectual functioning as well as improvements in long-term memory, and these effects are cumulative over time.

The heart meditation is amazing. The recording of sound, vibration and guided words were heartfelt. I felt energy in waves as I listened and felt various sensations of heat, tingling, and muscular tension release as I become one with the recording.  A sincere thank you for making these recordings available to us in search of an enlightened path with the help of sound and vibration. 
Stress: We all deal with it, yet we know how much better off we’d be — both physically and mentally — if we could only get it under control and find stress relievers that really work. While stress can be a positive, motivating factor at times (such as when you’re under pressure to perform well at work or to ace an important exam), more and more research shows that chronic stress impacts the body in ways similar to a poor diet, lack of sleep or sedentary lifestyle.

When tuning instruments that can produce sustained tones, beats can be readily recognized. Tuning two tones to a unison will present a peculiar effect: when the two tones are close in pitch but not identical, the difference in frequency generates the beating. The volume varies like in a tremolo as the sounds alternately interfere constructively and destructively. As the two tones gradually approach unison, the beating slows down and may become so slow as to be imperceptible. As the two tones get further apart, their beat frequency starts to approach the range of human pitch perception[1], the beating starts to sound like a note, and a combination tone is produced. This combination tone can also be referred to as a missing fundamental, as the beat frequency of any two tones is equivalent to the frequency of their implied fundamental frequency.
There's nothing like anxiety to annihilate your sense of humor. It would follow, then, that it's impossible to feel stressed when you're hunched over in a fit of giggles. Studies have shown, in fact, that laughter not only relieves tension, but actually improves immune function. Swap jokes with your friends. Rent a funny movie. Stop taking things so seriously!
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.
Brainwave entrainment is a colloquialism for such 'neural entrainment', which is a term used to denote the way in which the aggregate frequency of oscillations produced by the synchronous electrical activity in ensembles of cortical neurons can adjust to synchronize with the periodic vibration of an external stimuli, such as a sustained acoustic frequency perceived as pitch, a regularly repeating pattern of intermittent sounds, perceived as rhythm, or of a regularly rhythmically intermittent flashing light.
While originally brainwave entrainment was achieved by using pure tones of sound, it is now possible to take these tones and blend them with music, rhythms, and natural sounds, such as the sounds of flowing water, bird sounds, or waves lapping on a beach, creating extended tracts of varied and intriguing brainwave entrainment music for everyday use.
This is probably the most popular choice of frequency. The theta state is a state of tremendous stress relief. The benefits associated with theta level relaxation include improved concentration, reduced hyperactivity and improved memory. While in a state of theta relaxation, one’s blood pressure, breathing and heart rate all slow to a much more restful and healthy level that promotes natural healing. During theta relaxation one may also experience vivid flashes of mental imagery as the mind opens to memories or subconscious information that is not available to the conscious mind during the normal waking state. The theta state is a very deep state of relaxation that is excellent for deep hypnosis and mental programming.

I was failing to achieve deep physical relaxation and looking for ways to shift my consciousness. After trying out many ‘solutions’ - including some truly bizarre ones - I decided to stop for a while and take a break before my next attempts at astral projection. That’s when I was recommended X. I must say it has been instrumental in helping me enter the state of relaxation and vibration necessary to a satisfactory OBE.
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: The corresponding MP3 versions for those tracks can be found on my site here: I hope that helps.
I enjoy this one called: Cognition Enhancer For Clearer and Faster Thinking – Isochronic Tones (Electronic) … I seem to enjoy it. Any harm in just listening to this one every day for 30 minutes as a routine daily thing, just like brushing your teeth and making your bed. I would just use it at times when I’m working at my desk, maybe even reading the online news etc…Thoughts?

By the 1980s, entrainment technology had merged with advancements in microelectronics technology, making it possible to develop even more sophisticated audio and visual brainwave entrainment products for the marketplace. In the last two decades, a number of scientific studies have reported brainwave entrainment as an effective remedy for ADD, academic learning problems, and improving memory and cognition.
It might seem obvious that you’€™d know when you’€™re stressed, but many of us spend so much time in a frazzled state that we’ve forgotten what it feels like when our nervous systems are in balance: €”when we’€™re calm yet still alert and focused. If this is you, you can recognize when you’re stressed by listening to your body. When you’re tired, your eyes feel heavy and you might rest your head on your hand. When you’re happy, you laugh easily. And when you’re stressed, your body lets you know that, too. Get in the habit of paying attention to your body’€™s clues.

The Frequency following response (FFR), also referred to as Frequency Following Potential (FFP), is a specific response to hearing sound and music, by which neural oscillations adjust their frequency to match the rhythm of auditory stimuli. The use of sound with intent to influence cortical brainwave frequency is called auditory driving,[39][40] by which frequency of neural oscillation is 'driven' to entrain with that of the rhythm of a sound source.[41][42]