Isochronic tones are basically just a single tone with the volume being turned on and off at regular intervals. When you apply the same effects to music or a noise, it’s usually referred to as amplitude entrainment effects (in Mind Workstation anyway). When you apply the on/off effect to music or noise it’s usually done by targeting a specific frequency range in the sound and only turning that part on/off, leaving the rest of the music/noise untouched. What that does is allow parts of the music/noise to play without being distorted/interrupted, making it sound more pleasant to listen to. It produces a kind of fluttering sound as I like to call it and you can adjust the level of intensity.
The Transparent Corp forum – This forum is an invaluable resource for any brainwave entrainment user or enthusiast. Most of the feedback is obviously focused on the Transparent Corp software, but with over 20,000+ posts now you can find answers to the whole array of brainwave entrainment questions on there. (UPDATE: Sadly, the Transparent Corp forum has now been taken offline)
“Chronic stress,” however, is not so easily resolved. This type of stress is associated more commonly with negative health concerns. Chronic stress results when there are constant multiple stressors or major life stressors present (4). Money, work, and the economy were the most commonly reported factors contributing to chronic stress in the American Psychological Association’s (APA) 2011 Stress in America™ survey (3). Additional significant stressors include relationships, family responsibilities, family and personal health problems, job stability, and personal safety (3). Major events, such as the death of a loved one, divorce, and moving also can produce chronic stress.
From a brainwave entrainment effectiveness perspective, it’s my understanding that the response from isochronic tones stimulation starts to diminish over 30Hz and that 40Hz is about the limit for using them. So from what I’ve read on the topic a 100Hz beat wouldn’t work, probably because it’s too fast for the brain to process and synchronise with it.