Sounds and vibration can be toggled in the settings.

  1. Tap the Settings icon (cog) at the top right of the main screen
  2. Toggle the switch alongside the "Sound Effects" option (default: on)
  3. Toggle the switch alongside the "Vibration" option (default: off)

Sound effects are played when any option is tapped, when an answer is correct/incorrect, and when a new personal best score is achieved.
Vibrations are played when a chosen answer is incorrect.