Snapshots of Sound

Turning waves into numbers

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Digital audio measures a signal at regular instants (samples).
• CDs use 44,100 samples per second per channel.
• Playback rebuilds a smooth signal from the samples.

Steps

1. Measuring at regular instants
2. How many numbers?
3. More or fewer snapshots
4. The highest note
5. An hour of music
6. Between samples