Safe & Sound Parenting Group
My best explanation would be that the music is gated and certain frequencies are omitted in order to stimulate certain pathways of the brain. And as you go through the program, certain frequencies will be focused on in the songs that affect aspects of the brain. This particular program is focused on the social engagement system and the frequencies stimulate the vagus nerve.
It stimulates the middle ear muscles which hack your nervous system and put you in your ventral or "safe and sound" nervous system state. That's the shortest way to put it. He's written books, I would recommend searching for interviews he's done on youtube or podcasts he's done, I don't have a great link to give off the top of my head. But there's a whole lot to learn.
Parents and adult family members of children with PANS/PANDAS/AE.