SynthBilder is a program that transforms an audio signal into a sonogram image and vice versa. It allows one to study and examine the conversion of digital audio signals from the time domain into the frequency domain and back again. Additionally, SynthBilder demonstrates the use of windowing in the transformation of an audio signal. But, most importantly, SynthBilder will allow one to compose in a visual manner with sound, and provide a fine-tuned mechanism for sound synthesis.

see the following article for a brief introduction: [html] [pdf]