This project demonstrates how you can synthesize complex sounds using multiple sine wave tones. This project manipulates the tones in Scratch, which has its limitations. I also made a version using BeepBox, which is much closer to the original sound: https://scratch.mit.edu/projects/779705874/ ☛ Click the green flag to listen to a synthesized version of the Scratch Cat Meow, produced by manipulating the pitch and volume of four sine wave tones. The upper spectrogram shows the original meow sample. ☛ Click it to listen to the sound. The lower spectrogram shows a recording of the synthetic meow produced by this project. ☛ Click it to listen to the recorded sample I used to make the spectrogram. ☛ Click the buttons to the left to mute specific tones, and then click the green flag to listen to the result. ☛ Click the buttons to the right to play each tone with the original pitch and volume.
♫ ♫ ♫ Notes ♫ ♫ ♫ If you don't know what a spectrogram is, read this: https://en.wikipedia.org/wiki/Spectrogram To make this project, I opened the Meow sound in Audacity, and studied the harmonics (the horizontal "lines" you can see). I identified four strong harmonics, and wrote down their frequencies and how they changed over time. Then, I generated sine wave tones that matched the initial frequency of each of the harmonics. Finally, I imported the tones into Scratch, and used the pitch and volume effects to try to match the harmonics. The last part was the most challenging, because the pitch and volume effects take longer than a single screen refresh to execute. This causes a very noticeable "staircase" effect when changing the pitch quickly, and it also makes timing difficult. But I am still happy with the result - even though it is crudely synthesized, you can easily recognize the original meow :) ♫ ♫ ♫ Credits ♫ ♫ ♫ The Meow sound is from the Scratch sound library. The tones and the spectrogram images were made with Audacity.
