Basically, you can draw sound!

SpectroDraw’s interactive spectrogram lets you paint frequency content directly, adding a new dimension to sound design. Create sound effects, convert to midi, and more.

https://spectrodraw.com

In SpectroDraw, the spectrogram uses both hue and brightness to represent sound. This is because of a key issue: To convert a sound to an image and back losslessly, you need to represent each frequency with a phase and magnitude. The "phase," or the signal's midline, controls the hue, while the "magnitude," or the wave's amplitude, controls the brightness.



You can use SpectroDraw to create glitch sounds, drums, alternate reality sound effects, and other sounds that cannot be made with traditional synths. You can also use the eraser or noise remover tool to restore samples.

 

SpectroDraw Pro cost $39.99.