To quote from the page:
There are four paces to choose from: Delta, Theta, Alpha, and Gamma. Each pace has an ascending, descending, and constant version. The reason for this is that whether or not the pace goes up or down during the tape has an impact on the experience of the session; if a Theta session ascends from 4 to 8 Hz, it will generally become trippier as it progresses, whereas if it descends from 8 to 4 Hz, it will be more relaxing. The constant pace is there for those that prefer to have long, stable sessions.
You should choose the file you want based on the mood you’re in and how awake you are. First, go have a look over the descriptions of each pace; delta, theta, and so on. When you’ve found the one with the effects you’d like to replicate, consider how mentally agitated or fresh you are. If you feel drowsy or tired, go with the ascending version. If you feel awaken or energic, go with the descending version, or, alternatively, the constant version. If you for any reason find the noise to be bothersome to listen to, you can go ahead and mute the video and instead play some music or nature sounds in the background, but remember that the sound pulses are specifically there to help entrain you, not bother you.
