A study in two tones — their wavelengths, how they sum, and where they meet.
Tap a key or Space to listen
Fig. 1
Pressure along the air at one instant. Voice I and voice II
travel outward together; dots mark where they cross, rules mark where both begin a cycle at once.
Below, their sum — the wave your ear receives.
Fig. 2
Voice I drives the pen sideways, voice II up and down.
Simple ratios close into still figures; near-misses slowly turn.