What is the sound of serenity?

I found this video on YouTube.  It boasted that millions of people had used it to not only fall asleep but to sleep better as well.  After watching/listening to it for a few minutes, I am sure that it is true.  One of the things that we strive for the most in our lives and in our training is this sense of calmness.  In Aikido when we are confronted, the first stage is harmony.  Harmony within ourselves and then harmony with the opponents attack.  If one doesn't have harmony, then it is not Aikido.  Here is what harmony feels like and sounds like.  

https://www.youtube.com/watch?v=eKFTSSKCzWA&feature=youtu.be