[alnwlsn]

This must be the one I remember playing with around 2010. It used to be a java applet and you could draw in it like a paint program to make interesting sounds. After messing with it for a while I could kind of tell what was going on but not really.

Kind of reminds me of Slow Scan TV - I feel like with enough practice, you could tell what the image looked like without using a decoder.