Spectrogram Lab

This spectrum analyzer creates a graph of all the frequencies that are present in a sound at a given time. The resulting graph is known as a spectrogram. The darker areas are those where the frequencies have very low intensities, and the brighter areas represent frequencies that have high intensities in the sound.

What you need

Here’s what you do

  1. Hold your fingers against the front of your throat, where the small bump is and say “Zzzzz?” Does your throat vibrate?
  2. Now try saying “Sssss” (not “Essss”). What is vibrating? How is the “Zzzzz” sound different from the “Sssss” sound?
  3. Click the microphone button.
  4. Start off saying “oooooh” and then change into saying “aaaaah.” What do you notice about the image?
  5. Change the sound from “aaaaah” to “eeeeee.” How would you describe the differences in these images?
  6. Now try saying “Sssss” (not Esssss). How does this image compare to the vowel sound images?
  7. Make the sound “Shhhh.” How are “Sssss” and “Shhhh” spectrograms different?
  8. Click on the flute button now. How does the spectrogram compare to speech?

Special Thanks

to Chrome Music Lab. Chrome Music Lab is a collection of experiments that let anyone, at any age, explore how music works. They’re collaborations between musicians and coders, all built with the freely available Web Audio API.