You can hear these sounds yourself using a carefully crafted pattern! This phenomenon was discovered on HN years ago and I made it into this prototype back then

You can hear these sounds yourself using a carefully crafted pattern! This phenomenon was discovered on HN years ago and I made it into this prototype back then: http://thume.ca/screentunes/ http://thume.ca/screentunes/ It's cool that even more normal images produce enough sound to detect and decode. The loudness varies a lot based on display though, lots of LCDs you can't even hear it at all even with the exaggerated screentunes pattern.