This weekend I had my nieces and nephew stay over – three of them aged 6 to 11. They wandered around the house looking for ibeacons off the Calvium app, and amongst the audio there was a little surprise. A binaural recording of someone moving around quite close to you and then wandering away and going up a creaky staircase. “This one isn’t working Tant May!” starts the eldest. “Whats that?!!”
And then silence and each time I would look at them freeze and then suddenly move their eyes to the left. Suspicious and alert.
Its a very satisfying trick and interesting to see which parts of the track are the most convincing so following on from my other post about the power of sonic illusion and given that we are using binaural recordings in the Door into the Dark installation, I thought this would be worth a post.
The Science Part:
Binaural recording involves placing a tiny omnidirectional mic in each of your ears or in the ears of a carefully-crafted dummy head. The results can be very impressive, with lifelike stereo images in which the sounds seem to come from clearly-defined locations.
The illusion here is known as the phantom image. The differences between the left and right recordings trick the listener’s brain into constructing the perception of a continuous soundfield curving in from the sides, not just sound emanating from two fixed points.
The real world image is constructed using these differences in the following way. 1) Volume/Sound Intensity, 2) The miniscule sound delay in one ear from an off-centre source. 3)The change in the spectrum of frequencies that reach each ear because of the size and shape of your actual ear and the position of you head – causing an acoustic shadow. What this means for those who want to know is that a sound coming from the right hand side say is filtered in the following way. The right ear will get the full array of frequencies. Low frequences, with longer wavelengths will be able to bounce around the head in the way that Long Wave Radio can get to Bristol from France, but high frequencies are filtered out. Yes you can work this all out in a fast and automatic way below the level of conscious experience.
Assuming you are standing in at sea level and the air is at room temperature sound from one side will reach the facing ear 0.6 miliseconds before the other ear assuming a 20cm head diameter. Brain nerve signals are at best a third of the speed of sound.
Other than the fact the science is all very snazzy there is nothing really that special or new at least about binaural.
The invention of the telephone kick started the idea of stereo into life and I very much like the story of this theatrical show in Paris
In 1881, French inventor Clement Ader known for bringing the idea of military aviation to life, setup the first binaural audio transmission by connecting a series of telephone transmitters across the front of the stage of the Paris Opera House. Listeners about two kilometers away were able to hear the action onstage by holding two separate telephone receivers to their ears.
The technology was later commercialized as the “Théâtrophone,” and used to broadcast opera, theatre, and eventually news bulletins to hotels, cafes, clubs and home subscribers. At the time, it cost 50 French centimes for five minutes of listening. The company ceased operations in 1932.
Exactly. I have already publicly stated my desire to confuse and beguile the masses in a nice and comforting way and so when ever are going to enjoy the sound of an invisible figure walking up a staircase just behind us. (And yes user testing shows that its the quite close and just behind us location that is the real spine tingler when it comes to binaural)
Binaural was used with chilling success in The Ring - which I saw at Brighton Festival last year. I was hugging my knees for most of time in the dark and had to rip my headphones off at several times just to get a breather. But when has binaural been used to dramatic effect to take you into a plesant environment. Perhaps super-real stereo is the sonic equivalent of the Uncanny Valley (a psychological phenomenon meaning that as animatronics, and cartoons become more real we find them more horrific – i had to run away from my computer screen watching this: ) Perhaps we are never going to find the near but not quite right mismatch between sense and reality pleasant.
This summer I was working with Colin one of the Punchdrunk original producers on a Jonny’s night time sound and light installation walk at the Birmingham Mac. We talked a bit about the use of fear in Punchdrunk’s work. The constant musical cues heighten tension in the same way as a horror movie and all of the works I have been part of have required audience members to be suddenly separated from their friends. Colin argued that they only use fear to open people – make them open to the experiences and hyperaware. Perhaps this has an element of truth but doesn’t quite ring with how I like to do things. The story about the sun and the wind is my final word on that matter – I read this book when I was four and the story has stuck
The Sun and the Wind
One day the Sun and the Wind decided to have a competition to see who was stronger. The Sun pointed at a man in the park below – lets see who is stronger and can get his coat off. I bet I can get it off faster said the Wind. Sure go ahead said the Sun. The Wind blew and blew and the man in the park held onto his coat more and more. To no avail could the Wind get it off him. And then the Sun had a go. And yes its obvious right – it wasn’t when I was four though. The Sun shone and shone and then the man took off his coat and settled under the tree for a snooze.
The moral stuck with me. You want people to get naked. You have to be nice. You want people to bare their souls? You have to be super nice.
So what are binaural’s fortes if not terror? When would you like to imagine the presence of people but know that they are not really there? When would it be a pleasant surprise to find out when you opened your eyes that the space you were imagining all along had changed. Could you for example create a work where someone is being moved by because of the audio they are listening to they imagine they haven’t until the great reveal of sight?