Putting on a pair of electric earmuffs changes your perception in weird and "unnatural" ways.
They uniquely offer control over the sonic environment. You can control the input to your two ears independently, and without any cause beyond 'the soundsource dictated to'.
From the perspective of a 'naive' creature evolved to take queues from sound about location, this is an utterly baffling phenomenon.
Let's pretend speakers don't exist, or we are back in the time when they didn't. Either way: this is a place where sounds are natural, arising from visually explicable sources.
Pretend this is true:
There is a sound on your right, which of course impinges on both your left and right ear (though unequally). Your brain says 'the thing that made that sound is on the right'. Your brain judges that sound to be a bark, made by a dog. It's not your pet, it's a wild agent running about the world, and it might or might not be hungry and interested in you for more than your personality. Your brain decides there is a threat, and you tense up.
Even though this conclusion could well be incorrect, it is a judgement your brain has made through inference from a situation. I am not a biologist, but I'm comfortable asserting that providing the sense-data to make such judgements is one of the primary functions of the auditory system.
You hear a second sound, also a bark, but this sound occurs at 'brain-left'. Well, the brain is pretty cool, and it says: 'there are two dogs, one on my right and one on my left'. The threat level just increased: these dogs, having read The Art of War, are attempting a flanking maneuver with the ultimate aim of getting themselves some flank-steak du vous.
You go frozen, waiting for more sound to give you clues as to these two dogs' location. You look from left to right, seeing nothing and settle into your tension looking straight ahead.
But then you hear a third sound, coming from a little in front of your brain-position. Your brain judges this sound to be some kind of elephant, at least of the big kind. It does not sound very pleased.
It's also snowing.
Your brain jumps, concluding: one of these two dogs is Hannibal. You're a militarily learned man, in the know when it comes to elephants' taste in climates.
You hear an elephant trumpet again, but this time your brain says it is behind you. Its source appears to be either a second elephant, or the one elephant, who is apparently quite sneaky and fast. A true feat of tactical trickery is clearly unfolding, and it doesn't look like it's going to end well for you.
You have a couple other senses, but let's say you are positioned such that you can't see either of the dogs or elephant. I don't know that it needs saying, but you can't taste, touch, or smell them either. You have no data other than sound to corroborate these auditory phenomena.
Since we are pretending this is all true, you are correct in all these judgements, strange as they are. Your (proper) reaction is to enter flight-or-try-to-flight mode; the elephant sounds huge, possibly has backup, and the dogs don't sound interested in negotiating.
Now pretend it is false.
Some of your sense data is wrong: there's just one dog, privileged with not quantum, but newtonian locational tendencies who actually happens to be six feet above you; the elephant turns out to be a waterfall and a mile below you.
Clearly, your earlier judgements were made in error. But that's not the point. The point is this: natural sound has natural explanations. If you hear something and conclude it is in a place, and then hear that same sound in another place, there are only three possible conclusions: one, these sounds were produced by different, distinct sources; two, these sounds were made by a single (mobile) source; or three, your perception is incorrect and these sounds are somehow not actually as they appear to your brain. In our visually explanable world, if you aren't hallucinating, it is one of the first two, and the sounds have a location which is roughly conveyed by their character.
But we don't live in a visually explanable world anymore. Sound can be synthesized.
'Unnaturally' producers of sound, headphones in particular, create sounds that are not visually explainable; these sounds are created by a chameleon source, a masterkey to the sound-lock. They need not have a 'real' location or have any 'natural' explanation. They don't have to conform to any of the patterns a brain is equipped to ascribe to them.
The sound we listen to via unnatural means often follows the rules that constrain natural sound, but sometimes, it doesn't.
I think--and this is an intuition, not a bulletproof and well-vetted theorem--in these cases the effect recalls the discombobulated feeling that accompanies lightheadedness or paranoia or another situation where you know your perception isn't right: something's being dishonest, something isn't quite right.
An interesting vestigial quirk.