use adobe audition, highlight a part of the frequency spectrum, then go file import bitmap, make shure your bitmap is 24 bit, then choose carve modulate into selecetion. experiment with frequency ranges to minimize sound corruption or maybe even use it if your into weird noise, here is an example with barely any noticible noise ,
if im not mistaken that song is pretty old, so it is beyond me how he did that during that time, the song is called equation, and the album is based on crazy audio science so maybe he invented a way to do it , before adobe or the other programs like photo sounder
If you apply it only at like 1/100th intensity (not sure if audition can do this since bitmaps can't have transparency.. maybe the modulate setting can be altered?) .. so it just changes the darkness of the background a bit rather than cuts a black hole in it..
You can make it so that it appears almost invisible (and has very very low impact on the sound), but then you multiply the image intensity in photoshop and it will become clearer..
Good if you want to hide something in there that people wont be able to spot by just checking the spectrum analyzer
yea you can adjust all sorts of settings, the reason i cut a black hole into it because when you compress to mp3 it hard core scrambles the spectrum and gentle images get scrambled into the mp3 coding easy.
im not shure, i think if you re save it to mp3 after it scrambles it to hell again, but i think you can watermark above the audibe range and put anything in there and it wont even be audible. audition is the " industry standard" for audio production. it handles all formats.