The effects are strongest while you are listening to the tones because your brainwaves are synchronized and tuned into the frequency range you desire at that time. After you've stopped listening the effects can still linger for a while afterwards. The timescale will vary from person to person and be affected by what you do after you've stopped listening.
I have many new age, meditation, classical and jazz cds that I use for relaxation. This Steven Halpern cd is now my favorite one. I can listen to it for hours on end while I read, write, use the computer, or just veg out on the couch at home or lounge at the pool. I especially love the tracks with the ocean wave sounds mixed in with the electronic music. I definitely am in the theta brain wave state while listening to it, and I know that's the reason it is so much more soothing than any other cd that I own. It is really great for eliminating any anger or anxiety that I may be feeling. I believe it's also improving my sleep. I give this cd the highest possible recommendation!
Second, brainwave entrainment is a workout for your brain. This means you have to gently ease your way into the process. I recommend that you begin with the 30 minute Alpha Light Meditation for a few days as your meditative component. Also listen to IQ Increase and Beta Relaxed Focus one time each during your day as you work, commute, run errands, etc.
You probably already know that sex is a great tension reliever, but have you officially thought of it as a stress-relieving practice? Perhaps you should. The physical benefits of sex are numerous, and most of them work very well toward relieving stress. Sadly, many people have less sex when their stress levels are high. Learn how to avoid this trap.
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.
Building on guided imagery, you can also imagine yourself achieving goals like becoming healthier and more relaxed, doing well at tasks, and handling conflict in better ways. Also, visualizing yourself doing well on tasks you’re trying to master actually functions like physical practice, so you can improve your performance through visualizations as well.
Some research suggests that the benefits from brainwave entrainment can last a lot longer, and still be seen for some time after you've stopped using it. Study participants have still maintained improved test scores a few weeks after the stimulation had ceased. Research on the long-term benefits has so far been minimal though, so how long the effects last is still up for debate.
Binaural beats are created from two different continuous tones, which when sent separately to each ear create a single beat inside your head. Isochronic tones are basically a single tone which is switched on and off at regular intervals. Imagine a single continuous tone playing on a stereo system and you’ve got your hand on the volume switch. Then once per second, you turn the volume off for half a second and keep doing that every second. For half a second the volume is off, for the other half a beat waveform is formed. The beat is cycling once per second per second, i.e. at a rate of 1Hz.
Exercise and stress research has typically focused on aerobic exercise. There have been consistent findings that people report feeling calmer after a 20- to 30-minute bout of aerobic exercise, and the calming effect can last for several hours after exercise. Recently, there has been an increased amount of research on the role of mind-body types of exercise such as yoga or Tai Chi. Unfortunately, there is somewhat limited research on the role of resistance exercise in stress management.
Gamma waves are the fastest of the brainwave frequencies (high frequency band of brainwave activity) which signifies the highest state of focus possible. They are associated with peak concentration and the brain’s optimal frequency for cognitive functioning – the 40 Hz frequency corresponds to a Schumann resonance band and many scientists, including Nobel Laureate Sir Francis Crick believe that it may be the key to the act of cognition. The Gamma state relates to simultaneous processing of information from different brain areas; information passes very rapidly.
If brainwave entrainment leaves you with unwanted side-effects (see below) or discomfort, you’re probably encouraging a range of brainwaves that are already excessive in some area of your brain. The way around this is to get a brain map to see what your brain’s strengths and weaknesses are, and see what (if any) brainwaves could use some encouragement.