Sound


So at last, my mysterious project is complete.

You saw Laura a couple of days ago as she arrived, straight out of the box. She was not quite as perfect as I would have liked, so the first step involved some surgery…

As did the second step. ‘Trust me Laura,’ I said ‘I’m a doctor’. Well, I’m a Reverend, and that’s as good as, right? I mean, with God the Cow on my side, how can I do wrong? A little release of intracranial pressure…

Ah, that’s better. And now for the pièce de résistance… And Binauralaura (Laura to her friends) is ready to begin to listen…

Binauralaura is my new binaural recording rig. Here begins the edumacation part of this post, so those who came for the titillation can now go watch Fox news and eat donuts.

To start, you should know that when you hear a stereo recording of sound or music – pretty much any recording – it is presented to your ear in a very different way to the way in which you actually hear in reality. There are many reasons for this, but the main one is that most sound recordings, and most music recordings in particular, use a somewhat artificial method to render their stereophonic sonic landscape. In a standard electronically-reproduced stereo domain, the stereo image is created from two point sources – your two hifi speakers, or two headphone speakers – each of which is fed by a discrete channel of recorded sound. All sound in a stereo field is thus contained in two separate, but interconnected, recordings – one for left and one for right. In simple terms, if a sound is only in the left channel, it will appear to come from your left. If it is only in the right channel, it will appear to come from your right. In almost all modern recordings, when an engineer wishes to make a sound feel like it is originating elsewhere in the stereo image – slightly left of centre, for instance – it is made slightly louder in the left channel than it is in the right. To make it appear to be right in front of you – or ‘centre’ as we say – then the volume is made exactly equal for both the left and the right channels. For over half a century, this result has been achieved by ‘panning’ the sound on a mixing console. A panner is simply a control that varies the amount of signal (or loudness) added to each channel.

In the real world, though, our ears don’t judge the position of a sound in space solely by its loudness. Certainly, loudness is one aspect of the mechanism, but there are numerous other factors in play. The principal one is a component of time. If you hear a dog barking somewhere ahead of you, and slightly to the left, one of your ears will be receiving a slightly greater sound pressure (loudness) than the other. But crucially, that same ear will be hearing the sound very slightly before your other ear does. The human brain can, in fact, differentiate time differences smaller than 10 microseconds between your two ears, and it is that ability which allows us to aurally locate objects in space with an accuracy of about 1 degree.(i)(ii) Up until very recently, this time component could not be easily recreated in a studio mixing environment, and since – like most things – the recording process is a trade-off between the achievement of perfection and economic imperative, the old panning paradigm is still alive and well (and dominant) in modern sound mixing facilities. I would make a rough guess that 99.9% of all music and sound you hear is rendered to stereo with crude analogue panning.

Now, some of you may be ahead of me slightly here, and interject: ‘But Reverend, what about a recording made solely with two microphones? There’s no mixing console involved there (so no artificial panning) and the sound of any object off centre to the microphones must arrive at slightly different times for each? Surely that’s preserved in a recording?’

Well, yes indeed. Two separate microphones (or a coincident stereo pair, to use the lingo) will indeed preserve the delay times inherent in the scene being recorded but they still don’t hear the world like our ears do.

The important thing to understand at this point is that when it comes to human hearing, our eardrums – our ‘microphones’ if you like – are only part of the story. There are several other key players in the process, the most important of which is our brain. Our brain and ears work together to ‘hear’ the world, and the way we hear is a lot more complex and clever than you probably ever stopped to think about.

One thing that every one of us knows (because our brain figures it out pretty much as soon as we are born) is that our ears are separated from one another by a head. Everything we experience in the realm of natural hearing is mitigated by this big noggin right in the middle of things. And our brain calculates our aural experience by taking it into account as it forms our sonic picture of the world. Likewise, we are accustomed to hearing our surroundings via two fleshy reflectors that funnel the sound toward the vibrating membranes that actually detect the sound waves. The complicated contours of our ears – the pinnae – don’t simply look like they do for decoration. The whorls and cavities of the ear surface impose certain kinds of characteristics on the sound that reaches them, and these help us with sound localisation, and, to a certain extent, with the perception of fidelity.

Which brings me all the way back to Binauralaura. Laura’s head contains a pair of high fidelity omnidirectional microphones that sit in her ears just at about the place where the outside part of the human ear canal would start.(iii)

Her silicon pinnae are created from a CT scan of real human ears and these and her head create an aural ‘shadow’ which will match, in a generic way, the listening field of most humans.(iv) This means that a recording made with Binauralaura, will sound about as real as an audio recording can sound.(v)

So if binaural recording is so magnificent, why isn’t it used for everything? Well, there is, of course, a catch. The binaural effect can only properly be discerned by wearing headphones. For the binaural image to remain coherent, the sound for one ear must not interfere with the sound for the other. Additionally, in order to avoid a doubling of the head and pinnae shadow (one gained from the recording, and then a second from the listener’s own head and pinnae), the reproduced sound needs to be played back as close to the listener’s ear canal entrance as possible. The most expedient method to do this is via headphones or earbuds.(vi) Wearing headphones to properly hear binaural sound is, in fact, analogous to the requirement to wear glasses to see 3D images (indeed, binaural sound is often described as ‘3D’ or ‘holophonic’ sound).

I’ve had some opportunities to take Laura out for a bit of a test spin, and so far, the results are pretty nice. Here’s a short clip. Remember – wear headphones or earbuds to listen to it. One thing you will immediately notice is the clarity and and detail of the sound space. If your hearing is fair, you may also detect one of the extraordinary features of binaural sound – something you will not hear in a conventional stereophonic recording – and that is the ability to localise sound height. Have a listen now, and see why I went to all the trouble to build Binauralaura.

Download Laura Listens

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Footnotes:

  1. It’s more accurate if the sound is in front of you. As it approaches the extreme sides, the ability to pinpoint its location decreases. []
  2. As an aside, there is a species of fly which is so small that its ears are too close together for its head to have any effect on time delays between them. Instead, it has evolved an entirely different and novel way of localizing sound. The trick it uses (its ears are physically coupled together, allowing it to detect sub-microsecond delays) is currently being explored as a possible microphonic technique. []
  3. Not where the ear drums are – there’s a technical reason for this that I won’t go into here, but there are versions of binaural heads that do place the microphones right at the end of the ear canal. []
  4. It probably has occurred to you that most humans have small differences in the shapes and sizes of their ears. Shouldn’t this mean that one person hears differently to another? Well, yes, that’s right. To make a really convincing binaural recording for yourself, you would ideally put microphones in your own ears, and record with your own pinnae and head shape. Indeed, there are methods for doing this. To me, it does seem rather sonically masturbatory, though… []
  5. There are numerous other impediments to capturing a sound recording that would appear as real as reality. Mostly this has to do with the way our brain constantly interacts with the environment – not just the sound itself – to modify what we hear. And, in fact, what we think we hear is nothing like what we physcially hear. This problem is never really likely to ba addressed with a mechanical recording system. Until we have some kind of direct ‘neural recorder’ you can never really expect to experience a sound recording that is like really hearing something. []
  6. There are ways of achieving a serviceable binaural illusion in stereo speaker systems, but they are expensive, dependent on room acoustics, and require the listener to sit in a ‘sweet’ spot. Needless to say, all this is even less appealing than wearing headphones. []

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This is my new assistant. I am about to augment her for my secret project. Hint: she is not a Roman.

This is what I got in the mail yesterday. I figured that as one gets older, it’s de rigeuer to enhance one’s best assetts with silicone, right?

Heh. Just kidding. I have a project. It should be interesting. I’ll tell you all about it as I go.

Those of you who visit the Cow to read my skeptical take on all things weird and woo might be interested in my new blog Hummadruz. On Hummadruz I’m focussing exclusively on matters of sound & music – my own fields of expertise – and the huge amount of nuttiness that can be found therein. To kick off, I’m taking a look at a phenomenon that’s currently in the news: The West Seattle Hum. The Hum is a strange vibrating buzz that appears in West Seattle from time to time, but has manifested quite significantly over the recent Labor Day holiday.

I hope you’ll come and join the discussion over at Hummadruz. I am always on the lookout for weird and wacky audio phenomenon to examine, so if you have any favourites, be sure to let me know.

Yes, it does look exceedingly amusing, but it is very very effective.

The Huffington Post is carrying an article at the moment which is headlined:

Japanese HOLOGRAPH Plays Sold Out Concerts;
Science Fiction Comes To Life

The caps are theirs. Needless to say, once again this is not a holograph. Or a hologram either. In its typical air-headed style, the HuffPo goes on to delineate the fizz of the story while entirely missing the interesting bits:

In what is surely a terrible omen not only for musicians but also the continued existence of the world as we know it, holographs are now playing sold out concerts in, where else, Japan.

Firstly, I’ll reiterate (because stupid journalists just can’t seem to understand this) – the Hatsune Miku performances are NOT HOLOGRAMS. As I’ve said before on The Cow, we currently have no technology to allow anything like this as a holographic projection(i) The giant avatars are simply projections on a screen. There is nothing three dimensional about them, as would be the case for a genuine hologram. Here’s a still frame from Hatsune Miku’s video Romeo and Cinderella, in which you can plainly see the flatness of the character, and the screen on which it’s projected:

It’s an impressive technical display, for sure, but it’s just a very bright projector and a piece of clever animation. You could, if you were motivated, achieve the same thing in your lounge room.

Of course, the Huffington Post, could have carried a story about what is actually happening here, which is far more interesting than their stupid and inaccurate ‘Look at those wacky Japanese and their holographs’ fluff piece.

The ‘live’ Hatsune Miku concerts are in fact the culmination of what was originally a promotional concept for the Vocaloid 2 speech synthesis engine. Vocaloid 2 is software developed at Pompeu Fabra University in Spain with funding by the Yamaha Corporation. The application takes snippets of real human voice and arranges them in such a way that the many complex parts of human speech can be controlled, via simple programming, to make coherent speech and song. In 2006, Vocaloid 2 was acquired from Yamaha by a the Japanese company Crypton Future Media, who, with exceptional insight, packaged it for sale to consumers as a ‘personality': Hatsune Miku, ‘an android diva in the near-future world where songs are lost.’ The name Hatsune Miku is literally translated as ‘future sound’. Miku’s voice is generated from recordings of voice actress Saki Fujita. Using Vocaloid, musicians are able to program the Miku voice to sing whatever lyrics they choose along with their music.

When CFM released the software, they had the idea of creating several ‘mascots’ to anthropomorphize the Miku personality, and it wasn’t long before a programmer named Yu Higuchi released a freeware application, MikuMikuDance (MMD), which allowed users to easily create 2D and 3D animations based on the these mascots. A huge fanbase rapidly grew around this concept, with thousands of users interacting on Nico Nico Douga (a kind of Japanese YouTube) to produce videos of Hatsune Miku performances. The phenomenal success of Miku has spawned a family of new Vocaloids, such as Rin and Len Kagamine, Megurine Luka, Gackpoid, Megpoid and numerous ‘fan-created Vocaloids like Neru Akita and Teto Kasane.

Here is a video of Miku’s more sophisticated sister Megurine Luka,(ii) singing ‘Just Be Friends’:

The live Miku concerts with the 12 foot tall all-singing all-dancing projections of the character avatars are a natural result of the extraordinary popularity of the Vocaloid characters and their music.

Now isn’t that a lot more interesting than the Huffington Post’s (and others, I might add) flippant dissing of this story as an oh-my-god-singers-are-going-to-be-replaced-by-holograms-bring-back-the-good-old-days piece of sensationalism? Their silly take on it does nothing more than expose their white-bread middle-American sensibilities, and make them look like the insular conservatives they really are. The Hatsune Miku phenomenon might be slightly oblique to Western sensibilities, but one thing is very clear – here are large groups of passionate music fans having a genuinely good time. What the hell is wrong with that?

And besides, the music was made by musicians, not robots, people. And it’s damn catchy.

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Thanks to Joey for the find.

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Footnotes:

  1. You will notice here that I have used the correct forms of the words ‘hologram’ and ‘holograph’. You’d think journalists would take the time. []
  2. Megurine Luka is the first bilingual Vocaloid. Calm down Atlas – I said bilingual. []

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