If you like this exercise (or are tired of YouTube ads), download the MP3 or FLAC here: https://bit.ly/focus-study-binaural
Are you referring to the version I made available for public download a couple years ago from my "Lockdown" video? That is still available. However, I recently re-recorded it based on listener feedback, and made it usable by "everyone" (not specifically students).
Jody Hatton's Videos