I purchased a commercial liscense for software called Mind Workstation by a company called Transparent Corp. It's kind of like Protools but set up entirely for this kind of audio. It's wild. You can do so many different things with it, including biofeedback and neurofeedback if you get the right sensors/eeg headset. It's amazing stuff. This is one of the most powerfully sedating tracks I've been able to come up with. It uses a technique called variable induction and embeds the mind altering effect into the music with volume modulation rather than a separate track of tones.