AudioScope
What Can’t Your Eyes or Ears Pick Up?
Compare visible light and audible sound, then hear two tones at 440 Hz and 1,760 Hz.
Listen for the pitch jump
The second tone vibrates four times as fast as the first, a jump of two octaves. Both are within the typical range of human hearing.
Visible light is the portion of the electromagnetic spectrum our eyes respond to. Sound in air travels through pressure changes.