Dr. Harsh Trivedi of Vanderbilt's Psychiatric Hospital says the "digital drugs" use binaural audio files that have been around since the 1800s. "The thought is, if you can manipulate the sound using stereo headphones, if the frequency is off just a bit in one ear as opposed to the other, it can create a beat in between."
An online company sells the files as a download or on a cd starting at $16.95. "What the makers claim is it can help provide an euphoric effect as if you are high on drugs. There's nothing in the data that suggests it's actually true."