Trying to think of the name and then it came to me.. I doser... They are supposed to emulate all kinds of things and produce physiological responses. I am led to understand that , unlike binaural beats , they do not necessarily require head phones.
Anyway.. I have tried a good few and they make me fall to sleep... With the exception of the Sleep Angel I dose , which is designed to exactly that (hence I have had 100% success with that one) The others have not done a deal for me.. Though the big hitters...Hand of God and Gates of Hades left me feeling a bit sick y.
But that is just me... Given the success in the marketing , I guess they must surely work for some..
I myself remain very much , headphones not withstanding, more enamoured with the results I obtain from, Meta Music , The Monroe Institute, Solfeggio Frequencies and the works of Doctor Jeffrey Thompson.
This is a personal preference/experience though. If Isochronic tones work for you go with that..
If Dr Jeffrey Thompson's work may be appealing, here is a pack to pick from .
https://www.youtube.com/results?sear...ffrey+thompson