With its focus on full, cleansing breaths, deep breathing is a simple yet powerful relaxation technique. It’s easy to learn, can be practiced almost anywhere, and provides a quick way to get your stress levels in check. Deep breathing is the cornerstone of many other relaxation practices, too, and can be combined with other relaxing elements such as aromatherapy and music. While apps and audio downloads can guide you through the process, all you really need is a few minutes and a place to stretch out.
Although there is a general stress response pattern, there can be variations in the response according to the characteristics of the stressor (10). Individuals tend to respond differently based on the familiarity of the stressor. For example, the perceived level of stress and physiological response when giving a presentation to a group of work colleagues will likely be less than when presenting to an unfamiliar group. The stress response also varies depending on the level of perceived control one has over the stressor (10). If there is a way for one to actively cope with the stressor that is reasonable, then the individual usually perceives more control over the situation. Consider an individual who has to take a certification examination for work and has 6 months to prepare. He can adjust his schedule to accommodate study time. However, waiting for medical test results that show whether one has a serious illness does not allow a sense of control over the stressor, and the individual passively endures the stressor or may try to avoid the stressor. With this uncontrollable type of stressor, there is a more negative reaction with greater productions of cortisol, which can have damaging health effects because of the suppression of immune function (10).
When the brain is stimulated with pulsed sounds (neuro-electrical activity via the nerves originating from the ears), the overall activity of the brain will respond to and align with these pulses. By selecting the desired rate, the brain — via the frequency following response (entrainment) — can be naturally induced towards the selected brainwave state.
Over the past few years, brainwave entrainment products have made a great rise in popularity, reaching more people than ever before and peaking their interest with the many benefits ensured. We now have a continually expanding pool of options to choose from, as well as more information and scientific research on the subject than in the past.  Brainwave Entrainment audios, and the products being made with this technology are literally changing the game in the personal development field, and have become one of the largest catalysts in our recent evolution as a human race.  In fact, these audios may be one of the main contributing factors in unlocking the potential to tap into the untouched 98% of our brains that we are currently not using.

When you're having a hell of a day—good or bad—checking out for 10-15 minutes is revitalizing. Find a place where you can be alone (and definitely ditch the cell phone)—the attic, the bathroom, a quiet cafe, a big oak tree—and wipe the slate clean for a few minutes. Do whatever it is that relaxes you: Meditate, read a novel, sing or sip tea. It's crucial to take just a few minutes everyday to de-stress. It's not how much time you allot, but being consistent that's important.
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.

Entrainment is a phenomenon seen is a wide variety of different natural circumstance. In the field of chronobiology, the study of biological rhythms in living organisms, entrainment is the synchronization of a circadian rhythm with the rhythm of an external pattern, such as the synchronizing of women’s menstrual cycles with the phases of the moon or with one another in a group.
As Dawkins explains, ideas spread through the behavior that they produce in their hosts, which is what enables them to be transmitted from one brain to another. For example, an ideology — such as a religion — that causes its inhabitants to practice its rituals and communicate its beliefs will be transmitted to others. Successful ideas are those that are best able to spread themselves, while those that fail to self-replicate go extinct. In this way, some religious ideologies persist while others fade into oblivion.
This session shifts from the 14Hz sensormotor rhythm through beta to 40Hz gamma, and repeats the pattern over and over, constantly “revving up”the mind with each repetition. The process is stabilized with a 10Hz background alpha beat, allowing the brain a place to relax instantly, whenever a let up allows. Use this session any time, and for as long as required to get the job done. Take in a High Energy Espresso on long-hauls for a welcome lift. Works without headphones, but the best benefits can be found with them. The session finishes at a fast, revving 18Hz beta. For use mainly with eyes open, engaged in activity - with benefit to be gained from periodically closing your eyes briefly and relaxing.