Hi guys! I've a question related to this topic sound.stackexchange.com/questions/40726/… . My question is: since every sound texture we made (timbre) will be affected by noise and harmonic/amplitude distortion when I play it (from vinyl, very harsh, to cd, quite cold), which ALTER the timbre, how is possible that I feel the same "timbre" when I hear it? Or it is just "different" but I'm not able to tell a differences between the two?

Let say I take a synth, and I build up a texture with such of 10 partials, each with different amplitudes. When I play it on my studio, I have a fingerprint sound within my mind. Now, if the same sound is reproduced in other environments (different speakers/room, for example), I can hear the "same" sound, even if I would look at the waveform, it will be very different (some partials amplitude will be different, and also some new partial will be added).

But I still got it. Instead, if the same synth I edit manually (maybe drastically) some amplitude of the partial, I feel like the timbre "change". So why reproducing music doesn't affect timbre? It is just "slight" changes? Uhm... I don't think so. Vinyl for example will introduce LOTS of harmonics distortion.

Where's the "magic"?

@paizza I'm sorry paizza, but I think something may be getting lost in translation

I really am not sure what you are trying to ask. I get the general idea that you are asking about how different reproduction environments still sound like the same thing to us even though things like the medium it is played from, the equipment it is played back on and the room it is played in all impact the actual pressure impulses that reach our ear

but I'm not really sure what you are asking unless it's just that the magic is our brain

the source from the speaker comes out relatively close for any decent medium and our brain is extremely used to filtering out acoustic properties of the environment

CD's are described as cold and Vinyl is described as warm, but the fact is they are still producing very similar sounds. The difference is extremely minor. A trained ear may or may not be able to tell the difference, but half the time the issue is actually in the transfer between the mediums anyway, but even then, you're talking very, very minor differences

you can actually observe similar changes with different levels of MP3 encoding

someone with a good ear that knows what to listen for in the sound can tell you which file is higher bitrate even at fairly high bitrates, but it requires a trained ear and knowing what artifacts in MP3 sound like

99.9% of the population would be oblivious to it as it isn't the part of sound we pay attention to

naturally anyway

because it isn't information that is important to our ability to understand what we are hearing

and that's all in our brain

the raw amount of sensory data you take in every moment of every day is far FAR too immense and disjointed to make any sense of by itself

so the brain filters it down before it gets to you conciously

what someone with a "trained ear" is doing is basically overriding that filtering and instead focusing on the particulars of the sound to identify hard to spot subtleties, but that takes time to develop and concentration to do well

like, years

I'd say I was still developing my ability to hear spectrum well past the 6 year mark of doing sound and probably was still improving up to atleast 10 years in

past there it got to the point where it's hard to tell if it is still improving or not

hope that helps if I understood correctly

but that also might be part of the lost in translation bit

people pick up on the tempo and apparent notes of music easily, but as you mentioned, there is a ton of complexity in the actual sound waves that we hear beyond just a single frequency tone for each note

our brains simplify this down for us with what the note we're perceiving is along with some characteristic of the instrument making it, but by default we discard fairly large portions of the sound that aren't generally key for understanding speech (which is what we are really fine tuned for)

my knowledge on perception itself isn't all that complete, but if you read up on psychoacoustic compression, it actually works by discarding portions of sound that most people do not actually pull information from

in general, I know there are two main frequency bands that we rely on, but I forget what they are. One is the portion that gives us tone of voice and lets us identify the speaker and a lot of the emotional content, the other is the higher frequencies where the edges of syllables are found. This is what we use to figure out the meaning of words as it gives the hard breaks between different sounds within the word and is why we have trouble understanding someone who is mumbling

so for most people, there is this extremely heavy weighting towards both certain frequency bands and also certain contexts of sound that their brain highlights as important

people who tend to do a lot of mixing or are fairly technical musicians develop the ability to level out their weighting a bit because they have to regularly pull information from frequencies and sounds that most people don't need to pay attention to

it's really quite fascinating stuff

it's also why I always preface my answer whenever someone asks me what headphones I use because they are looking for a pair themselves

I use a $550 pair of SE-535s, but I wouldn't recommend them to the vast majority of people

they are really a technical tool and aren't worth it compared to much cheaper options for the vast majority of people

ok, so I did a quick refresher on musical terms, timbre is kind of like a pattern recognition

the room and recording mechanism may add their own characteristics, but we can still recognize the pattern

perhaps a visual example is a good way to explain it

if you see a rainbow on a black and white TV, you'll still know it is a rainbow because the shape and placement is what you expect of a rainbow

the same goes for the sounds of an instrument

you know what the instrument sounds like, and potentially even know what different styles of playing the instrument sound like. Those are patterns of vibration hitting your ear that your brain can recognize, just like the shape of the rainbow hitting your rods and cones in your eyes

sure "big room" also has a different impact than "tin can", but we're also able to recognize those patterns

just like we can recognize if we see a rainbow in the sky or on a gay pride bumper sticker

we can tell both what it is and what the context is

because both have their recognizable patterns

if you get really good, there are people who can tell you the approximate year that video was shot just by looking at how it is colored and how the motion looks

people are really REALLY good at patterns

and as for why the waveform can look so different, it's also partly because of how waveforms work

you'd be better off looking at something like a spectrograph for what you are trying to understand

waveforms are a representation of the rate of pressure change over time, not of frequency

you could have a really loud low frequency that wouldn't impact your ability to hear most of the sound that would completely dominate a waveform

on the other hand, a spectrograph will actually break out sound intensity by frequency

this makes it much easier to see the tonal content of sound visually

if you get good at reading them, it's pretty easy to pick out different instruments and sounds on a spectrograph

since it adds that very critical piece of information by breaking out the frequencies for us instead of having a visually unprocessable composite wave form

for more on understanding how they combine, I suggest reading on constructive and destructive interference

but effectively, the sound hitting your ears (or a microphone) is the sum total of all positive and negative pressure waves hitting it from any number of different sound waves moving through the air at the time

which means that if one frequency is going up and one is going down, then they cancel each other out when they hit your ear drum because one is trying to pull your eardrum in while the other is trying to push it out (that's an oversimplification of the physical way we hear, but it is effective for the purposes of this discussion)