Actually Naiw, that's mostly false, though your understanding of it is pretty accurate. Mp3, AAC, Ogg and every other comp algorithm do what is generally called perceptual coding.
The audio waveform is analyzed both instantaneously and predictively. Variable (often large) amounts of data are removed if it is decided that what remains will "cover up" what's missing. It's actually pretty damn ingenious, but it's anything but perfect and it's anything BUT high-fidelity.
The first thing to go is detail…NOT just frequency response. The fine phase relationships between channels that contribute to ambience, presence and imaging are gone… period. That great convolution reverb plugin that cost you an arm and a leg might as well not be there. The timbres of some instruments are degraded as the upper harmonics are reduced and shifted. That's just for openers! This is a subject that can be and is often discussed at reaaalllly long length-far more that we will here. For now, let us simply apply some l-o-g-i-c .
If Mp3 was so indistinguishable from the original there wouldn't BE Ogg, AAC, DTS, TTA, OFR and on and on as they keep trying to improve on what evidently needs improvement. ALL of these damn codecs were created to make up for the fact that HDD's were smaller then, downloads took forever and it was calculated that "the masses" could barely tell the difference and wouldn't really care as long as it meant more songs on their iPods.
The thing about saying "mp3 for example was created to trim the filesize down by cutting out a range of frequency's that no human can hear anyway. i dont call that a loss since i cant hear it." smacks of someone who grew up starting with Napster and is so acclimated to the mediocre crap that streams over Shitify and such that they simply don't know what they're missing because they never learned to "hear" it to begin with.
Thought for the day:
Isn't it odd that 99% of people have NO trouble at all seeing and understanding what JPEG compression does to images but somehow can't make the leap to hearing and understanding how MPEG does the exact same thing with sound.
Finally, the point waay back in the beginning (before all of this BS) was simply that those of us in the industry would appreciate it if Apple could be bothered just once in a while to NOT continually make things more difficult for us and force us to work around an endless series of aggravations just to maintain our loyalty to their damn platform.
