For his latest project, pioneering sound recordist and sonic sculptor Chris Watson turned his attention to the seldom-heard phenomenon of ravens gathering to roost, creating a unique audio experience deep in Northumberland’s Kielder Forest.

Led by a guide sharing ancient raven lore, the audience entered the deepest part of the wood where, with darkness falling, the air suddenly filled with the sound of two thousand birds arriving in the canopy overhead...

Entitled Hrafn: Conversations With Odin, the work follows Watson’s Hy-Brasil installation at Opera North in Leeds, which sound company Pro Audio Systems regards as one of its most interesting projects of 2014. Composed by Chris Watson and produced by Iain Pate – commissioned through Jerwood Open Forest and a partnership between the Jerwood Charitable Foundation and Forestry Commission England – it draws on folkloric tales of how Odin, ruler of Asgard, would send out his two ravens, Huginn and Muninn, every day to fly around the Earth and report the happenings of the world to him at night in the Halls of Valhalla.

It’s not the sort of thing audio hire companies get asked to do every day – but Pro Audio Systems struck a winning combination of determination, ingenuity and the right equipment. The sound design itself comprised 12 Meyer Sound UPJ-1P loudspeakers suspended within the forest canopy as an ‘outer ring’ some 10m above the ground. Five metres higher up, four more UPJ-1Ps formed the inner ring, and all the loudspeakers were fitted with weatherproof hoods to keep out the worst of the wind and rain. Self-powered loudspeakers simplified the cabling infrastructure, and once concealed with branches and moss, the installation was all but invisible.

The multichannel Ambisonic playback used to create the sound of the birds was controlled from a position 75m away from the performance area, and was generated by an Apple Macintosh computer providing 12 discrete outputs to the loudspeaker system. Able to create virtual sound sources above and below the listener, Ambisonics allowed the producer of the piece to think in terms of source directions rather than loudspeaker positions – in this case the spatialisation created by Tony Myatt contributed significantly to the way the work sounded and why it was so well received. Portable power was required to drive all this technology, and a super-silent generator was set up a further 50m away so that it did not add to the ambient noise.

‘I was very impressed by the quality and transparency of the technology, the speakers in particular,’ Watson observes. ‘The sounds appeared real to many people, and it doesn’t get better than that...

‘Several people told me they could not distinguish between the sounds of the installation and the actual sounds of the forest. Some local birds also responded each evening; a robin would join in at the start, a few ravens also flew in to check if it was an actual roost and each evening after sun set, as the piece concluded, two and sometimes four tawny owls would join the installation finale.’

‘Hrafn was a brand new production in a pretty remote location with relatively challenging conditions,’ offers curator and producer Iain Pate. ‘Our success was dependent on having a professional team who worked hard on the planning of the event, combined with really good kit that was well prepared before we got on site.’

Tony Myatt’s technical expertise in numerous fields concerned with multichannel recording and playback was central to the realisation of the project: ‘Transparent was the best word we could think of to describe the experience of hearing the Meyer UPJ-1P rig in the forest,’ he says. ‘I’d specified these loudspeakers because of the power and fidelity we needed to support the bespoke Ambisonic decode I’d developed to present Watson’s work over a large area of Kielder forest. We needed the replay to be ‘invisible’ for the Hrafn to be successful, and it was.

‘With the loudspeakers hidden high in trees at a remote location of the forest, and without any technology visible to the audience, listeners’ perception of the full-surround audio was well supported by the woodland environment. I often try to create surround audio presentations that can appeal to human spatial perception, but rarely do I have the chance to do this visually as well as aurally.’

Watson used a combination of sound recording methods to capture the amazingly clear sounds he featured in Hrafn, including some full-surround Ambisonic recordings. ‘During soundchecks, bizarre as it sounds, almost every time a section of the work was played which contained Ambisonically-recorded Jackdaws, Chris and I turned to check if the birds were really there in the forest,’ Myatt says. ‘We knew they weren’t, but their spatial presence was so startling each time we heard them, we had to check if they were real.

‘The sounds of the forest also blended into the piece and the local wildlife, in turn, responded to the sounds they heard. The UPJ-1Ps performed superbly, without colouration, compression or strain, or any sense that the audio surrounding and above the audience was being delivered by loudspeakers.

‘Small things stick in my mind from installations like these,’ he adds. ‘In Kielder, in the first few moments of playback after I’d measured, calibrated, and coded the loudspeaker location data into my audio software, a seasoned professional from Pro Audio – with years of Meyer Sound gigs under his belt – listened, looked around, drew a long breath and very quietly whispered two slightly-colourful words to himself. It’s moments like these that tell me the surround software is probably performing okay.

‘It takes the collaboration of many like-minded people to realise a project like this,’ Myatt reflects. ‘Without an audio company with the ambition and enthusiasm to explore new ground in the way Pro Audio have done for us so often, sound artists couldn’t push the boundaries of new work and create such extraordinarily original and powerful artworks.

‘We all need companies like Pro Audio to say, “Yes of course we can suspend 12 Meyer Sound UPJ-1Ps in trees, in the middle of a remote forest, in the rain, for a week. No problem”.

‘I can’t thank Pro Audio enough for the quality of their work. Not only do they have the will, energy and knowledge to pull off an event like this, they also do it to the highest standards of audio quality, safety and efficiency; and always with a smile.’

See also:
Flying into the Dawn (Sound installation by Thor McIntyre-Burnie)
Interview: Aleks Kolkowski – In Search of Perfect Sound (Sound installation by Aleks Kolkowski)
Recording the ‘Ice Whisper’ (Arts recording project by Juergen Staack)
Meyer Sound dives into immersive art installation (Sound installation by Jana Winderen)