A little background and more context about this trivia
First appearing in the mid-90s, the ESP (Electronic Skip Protection or Electronic Shock Protection) button enabled a data buffering feature on portable CD players to help prevent audio playback from skipping when the device experienced physical shocks, such as being in your pocket during a jog.
The ESP button was a significant innovation for music enthusiasts who were constantly on the move. Prior to its introduction, portable CD players were notorious for their sensitivity to movement, often causing music to skip or stop altogether with even the slightest jolt.
When activated, audio would be stored in RAM before being piped through the digital-to-analog converter, giving the CD player time to find where it left off reading and allowing playback to continue when it would otherwise skip.
Early on, the feature could only buffer about three seconds, but it naturally faded out of necessity amid the rise of flash-based MP3 players. These newer devices could store entire music libraries in solid-state memory, which had no moving parts and thus was not susceptible to skipping, rendering the ESP button obsolete.