What is audio meant to do?

[Blumlein 88]

I think the answer is small flying drones with small speakers. An algorithm can position them where they need to be for each recording and play back real sources instead of virtual ones.

Prior to that I expect we'll replace Dolby Atmos with Dolby Stratos and a few more. Then when we get to Dolby Galaxy you'll have as many speakers as there are stars in the sky. At which point it will all be perfect. Which won't keep Dolby from releasing Dolby Universe a few years later. Then I'll finally be able to record and accurately play back Cicadas in the summer where I live, and have it sound real.

 

[Wombat]

My OP was an attempt to demonstrate why this goal is logically flawed. I guess you disagree?

It is an ideal. It may not be realised now but then it may be in the future.

The term audio is not strictly defined so it can mean different things to different people. You can only get opinions on this and thus not definitive input.

Even at a live performance a listener hears it from only one of many possible listening positions. A solution would need to be audibly 3D holographic.

It is of little interest to me except as a technical matter.

 

[RayDunzl]

I suppose the Holodeck is what we all, even if secretly, want...

 

[andreasmaaan]

It is an ideal. It may not be realised but then it may be.

The term audio is not distinctly defined so it can mean different things to different people. You can only get opinions on this and thus not definitive input.

Ok, but my contention is not merely that it can't be realised in practice, but rather that it can't be realised in principle (at least so long as there are audible reflections present in the performance space).

In case my OP wasn't clear, by "audio" I mean acoustic event(s). By "audio recording" I mean the process of using a microphone to commit a recording of an acoustic event(s) to a medium from which it can later be reproduced. By "audio reproduction" I mean the reproduction of that recording as an acoustic event via speakers or headphones.

 

[Kal Rubinson]

Thanks, will be interesting to track this down and give it a listen.

It is interesting but not very enjoyable.

 

[andreasmaaan]

I think the answer is small flying drones with small speakers. An algorithm can position them where they need to be for each recording and play back real sources instead of virtual ones.

Prior to that I expect we'll replace Dolby Atmos with Dolby Stratos and a few more. Then when we get to Dolby Galaxy you'll have as many speakers as there are stars in the sky. At which point it will all be perfect. Which won't keep Dolby from releasing Dolby Universe a few years later. Then I'll finally be able to record and accurately play back Cicadas in the summer where I live, and have it sound real.

Haha, probably

But if you look back at my OP, so long as there is both direct and reflected sound contained in the recording, the "problem" (I use quotation marks because it very much an abstract problem) can't be solved no matter how many speakers there are in the reproduction space nor what their locations are.

The key sentence in the OP is this one:

In the original performance, we have a mic receiving direct and reflected sound from different points all around it in the performance space. Then, on playback, we have a speaker reproducing all those sounds from one point in space.

 

[Wombat]

I think the answer is small flying drones with small speakers. An algorithm can position them where they need to be for each recording and play back real sources instead of virtual ones.

Prior to that I expect we'll replace Dolby Atmos with Dolby Stratos and a few more. Then when we get to Dolby Galaxy you'll have as many speakers as there are stars in the sky. At which point it will all be perfect. Which won't keep Dolby from releasing Dolby Universe a few years later. Then I'll finally be able to record and accurately play back Cicadas in the summer where I live, and have it sound real.

Google, Apple, et all will then put it in a light bulb that talks to you.

 

[tomelex]

I think the idea behind "audio" was to recreate an audio event in another place, at the same time...or then record it for recreation at a later time.

The issue is if we can not recreate the original surroundings nor the original transmission paths of the instruments then we are left with a huge compromise. Until we get the holodeck from startrek we aint gonna get there from here. So, we are left with what we have, theoretically the more reproduction channels the closer we can get "with our existing non holodeck technology".

A real binaural recording, with you at the event, with mics in your ears, going to a two channel recording system (one for each ear and played back over headphones) is the ultimate system we have now for transporting you to the original event.

And we did not pursue that means of recording so we are left with the speakers approach, and never enough channels/speakers to do more than give a hint of what is possible with existing technology. The speakers type thing we have, tries to bring the event to your room, your space is not the same as the original event, and your two speakers in no way can create the wiggles of air that each ear would have heard at the original event.

Contrast that to a binaural recording to see which one gets closer to the goal of replicating the original event as far as audio is concerned.....

 

[Guermantes]

I believe there will always be some aspect (audio or otherwise) of the original event that escapes whatever container we create to replicate it. Philosophically speaking, we won't be able to create a representation that is identical to the event in the same way that language, photography, maps, film cannot capture the world-as-it-is. But they are instead worlds in themselves, and so we should revel in them.

Otherwise we may end up with a map that is the same size as the territory it represents: https://en.wikipedia.org/wiki/On_Exactitude_in_Science

 

[andreasmaaan]

I believe there will always be some aspect (audio or otherwise) of the original event that escapes whatever container we create to replicate it. Philosophically speaking, we won't be able to create a representation that is identical to the event in the same way that language, photography, maps, film cannot capture the world-as-it-is. But they are instead worlds in themselves, and so we should revel in them.

Otherwise we may end up with a map that is the same size as the territory it represents:

I find this notion intuitively very compelling. I also see audio reproduction as about reproducing a recording as opposed to the event captured by it.

Yet I also like thinking in the abstract about the reasons why this might be so.

Apart from the problem I suggested - that is, of (non-anechoic) recordings per se capturing both direct sound from the original source and reflected sounds from a multitude of other sources, while reproduction systems per se reproduce both the direct and reflected sounds from only one source (or more, but in any case never able to fully separate the source of the original sound from that of the reflections) - can you think of any other reasons why aspects of the original event would "escape the container"?

 

[Guermantes]

. . . can you think of any other reasons why aspects of the original event would "escape the container"?

Affect and engagement. The whole idea of recreating the event is predicated on recreating the experience and there is more to this than the acoustic dimension, though that is the primary focus.

Perhaps holodecks will be the closest we ever come unless we can inject the experience directly into our brains and thus make us believe we are experiencing something that is not actually occurring. Still our attempts at capturing acoustic events do produce affect of their own type. I believe a lot of this has to do with musical cognition so that elements can be abstracted from the recording, even a poor one. There is also the fact that listening to recordings is a skill we have developed -- we can unpack them in our minds and create aural scenes.

Still something eludes us and that is why we are chasing ever higher fidelity.

 

[Blumlein 88]

Haha, probably

But if you look back at my OP, so long as there is both direct and reflected sound contained in the recording, the "problem" (I use quotation marks because it very much an abstract problem) can't be solved no matter how many speakers there are in the reproduction space nor what their locations are.

The key sentence in the OP is this one:

In the original performance, we have a mic receiving direct and reflected sound from different points all around it in the performance space. Then, on playback, we have a speaker reproducing all those sounds from one point in space.

You under-estimate the potential in beam-forming from multiple sources, and AI to figure out how to make it work. Also remember we don't have to recreate the entire soundfield in situ, we only have to create the soundfield as it would exist in the close vicinity of the listener's torso and head.

 

[svart-hvitt]

I have a saying: standardization is the enemy of innovation. Once we standardized on 2-channel audio, we put a lot of restrictions on ourselves for sound reproduction.

Horror!

No Neopolitan pizza for you my friend!



PS: The introduction of one standard doesn’t mean one can’t have another standard. Americans discarded the Neopolitan standard many years ago. So they introduced «American pizza», and then came their next big innovation, Pizza Hut.

 

[svart-hvitt]

Where’s the science in this discussion?



A live event means we see and smell (use our senses) differently than when we play back. If you focus on vision, your hearing gets impaired. We’re not multitasking machines with multiple cores.

Because we use our senses differently during a live event, the playback will be perceived differently.

Add to this other factors, like psychological ones.

Maybe we should ask for being blinded and being transported to random live music events to experience (some of) this in practice?

 

[Blumlein 88]

Horror!

No Neopolitan pizza for you my friend!



PS: The introduction of one standard doesn’t mean one can’t have another standard. Americans discarded the Neopolitan standard mange years ago. So they introduced «American pizza», and then came their next big innovation, Pizza Hut.

Yes Neopolitan pizza is the way to go.

 

[Wombat]

Short answer. Give enjoyment.

Some folks are more picky than others, or less picky than others.

 

[Cosmik]

On a side note, I can think of only one possible way in which a recording might be able to be said to capture a performance according to the model I discussed in the OP. This would be when the recording itself is taken in an anechoic chamber.

I've never heard a recording taken in an anechoic chamber - has anyone hear ever heard or made one? I imagine it would sound as unnatural as the experience of being in an anechoic chamber. Or perhaps after an adjustment period, you'd get used to the way the sound you hear from your speaker(s) contains only reflections from the room your speakers are in.

I think this is another area where science has not defined the approach, but pragmatism has.

Recording pioneers quickly understood the problem of overly reverberant recordings, and instead of recording with a single mic from the audience position, they began placing mics much closer to the performers in order to reduce the proportion of reflected sound being picked up - a.k.a. closer to anechoic. Some ambience was included, however, and with multiple mics and mixing desks the balance could be tailored precisely.

The result when played over speakers sounds more 'real' than the obvious approach - but also changes the character of the sources relative to what would be heard in the audience.

With a good system, and listening intently to the music (rather than as background to cooking the dinner), I think more 'purist' recordings - with more distant mics - can sound better.

There are some articles about it here:
http://www.regonaudio.com/

 

[Cosmik]

And of course this is related to the 'hear through the room' controversy. In a live performance, the listeners 'hear through the room' to the acoustic sources and separate the reverberation from the sources. But the recording doesn't provide enough information to allow the listener to do that, and so the recording sounds a lot more reverberation-heavy than the original performance if mic'ed from the same position

A close-mic'ed recording coupled with a real listening room restores some real acoustic space (even though it's just a domestic room's acoustics) to the performance. In my mind's eye it is adding a bit of genuine 'spatiality' to an otherwise static recording which is why I don't want to remove it by 'correction' (surely the ultimate aim of 'room correction'..?) or speakers that beam directly to my ears.

 

[Guermantes]

I was wondering when your avatar was going to make an appearance in this discussion . . .

 

[oivavoi]

Moreover, even if a recording is captured by a transparent microphone (or two if we make it binaural) and stored on a transparent recording medium, this recording cannot discriminate between the direct sound and the reflected sound at the point in the performance space at which the microphone(s) is situated.

And it is this mixture of direct and reflected sound which becomes the signal that is then reproduced by a speaker (or headphones or multiple speakers).

How, in light of this, can a reproduction system hope to fulfil the goal of reproducing a "performance" in a way that is audibly indistinguishable from the original?

In the original performance, we have a mic receiving direct and reflected sound from different points all around it in the performance space. Then, on playback, we have a speaker reproducing all those sounds from one point in space.

I'm unashamedly hoping to recreate a real acoustic performance in my home. For the reasons you mention, it seems logical to me that an acoustic recording that was created with omni mics which capture sound from all around it, should be reproduced by a omnidirectional point source speaker. So I bought the only such speaker in existence that I'm aware of... But have been waiting for quite a while for delivery. https://www.morrisonaudio.com/design-overview/

EDIT: but since quite a lot of recordings are not made that way, I also have a pair of more conventional box speakers as well, for dry studio recordings (the Dutch & Dutch 8Cs).