There is no "Full" Walkthrough, because the Sounds you have to place correclty are randomized at the bottom of the screen.
Some People made Walkthroughs, but you can't use them to place the sounds like in their vids because of that random generation.
The Vids i'm linking are only good for a easier Game, but you have to use your ears anyway.
For this Achievement you have to play Level 4-25
without pressing + at any time ( Level 1+2 don't have Layers, Level 3 is a Layer-Tutorial ) .
Since it is very hard to hear a specific sound if some diiferent ones are played simultaneously, it is a little easier to watch vids of someone switching between layers and listening to each sound.
It worked for me, so listen to each sound in the vids, compare with your sounds to place and you should be fine in 6-8 hours or faster if your hearing is better.
Just remember to use the hint-system AFTER you got
Open Spoiler for the videos: