Binaural Sound: Salford Acoustics
Many moons ago I graduated with a degree in music, acoustics and sound recording. It seems like a lifetime ago I lived in Castle Irwell in Lower Broughton, Salford.
Back then, we were recording on reels, minidiscs and DAT tapes in basement studios, creating dance songs out of ripped paper samples and standing on street corners in Salford with terrifyingly expensive calibrators...
My dissertation was a theoretical model for predicting neighbourhood noise levels for an outdoor music event, depending on where the stage was positioned.
In between my studies, I fell into radio by accident. Originally a desk driver at Shock Radio, the University of Salford's student radio station - I ended up on air by complete chance when the presenter I was meant to be engineering for failed to turn up for their shift. I remember the first time I put the fader up and had to talk...Aargh. Two years later I was awarded female presenter of the year by my peers.
I was the only woman to graduate on my course in 2005. But I loved it. And the lessons I learnt over those three years - are still of value in my present job some 15 years later.
I developed a nerdy hunger to know a little bit about everything to do with sound. Fortunately, my career over the last decade has allowed me to work on everything from on-location current affairs farming programmes, to specially crafted music docs to audio dramas like The Archers - all avenues which have continued to feed my inner audio geek.
So when I reached out on social media for help on binaural sound research last week, I was especially stoked to see a name from a familiar organisation on my timeline, offering to help.
Dr Ben Shirley, is a senior lecturer at the University of Salford. He lectures on spatial audio, music technology, audio production and post production on the BSc, BEng and MSc courses. But he also works for one of the university's off-shoot companies, Salsa Sound, which vavavooms audience audio experience for live events, including football broadcasts.
From swopping out commentaries, to changing the level of on-pitch sounds, to providing a service for impaired users - they've founded some great tech to capture rich, immersive experiences for live sports broadcasting.
Their research was founded by a trial with Chelsea Football Club to explore new personalised ways for the audience at home to hear every whistle and feel the kick of the ball.
In fact, they'll be piloting their sports audio solutions with Manchester City FC in the coming season... "bringing the sound of the Etihad to fans wherever they are..."
Which is really interesting, because personalisation is something I've already been hearing about in the wider video market with one of my clients' podcasts too, SES's Satellite Stories.
In the final part of my blog series on binaural sound, we look at why spatial sound is back on the map, and where the possibilities are - for research, for audio producers and the commercial world.
Clare Q - Why the sudden rise in interest in binaural sound?
Ben A - The increased use of headphones generally, no doubt driven by ubiquitous mobile devices, has certainly led to renewed interest. Use of binaural sound in VR/AR/XR applications is also a big driver. There’s also been a lot of research over recent years which has increased the quality of binaural reproduction and the percentage of people that it works for.
Q - More people are engaging in VR, has that helped too?
A - Definitely, not least because VR applications use head tracking which can make binaural sound much more realistic and effective.
Head tracking enables an application to recognise and identify a user's head movements - head tracked binaural on mobile devices has only really been possible in recent years as processing capability has increased. There are a number of manufacturers developing headphones capable of head tracking now which is likely to push binaural still further, at least once the price comes down!
Q - What kind of kit are you using in your labs?
A - A lot of the binaural recordings I do are recorded with Soundfield mics. Soundfields do ambisonic recordings and ambisonics is the format that VR, Facebook 360, YouTube 360 etc use for binaural rendering. It’s an old format but has become really useful as VR has taken off. Ambisonic mics allow capture of sound in 3 dimensions and this can be decoded to binaural, it also has the advantage of bein very easy to rotate so perfect for head tracked binaural applications.
There are a load of other ambisonic mics available now which are gaining a good reputation, the CoreSound’s TetraMic is one, also Sennheiser’s Ambeo though I’ve not used these yet.
I also do some recording using Roland CS-10s which are ear buds with mics in them, these don’t allow head tracking though.
For composing binaural recordings, and for mixing them I use pretty standard mic techniques and a number of plugins to pan the sounds where I want them in 3D space.
Blue Ripple’s O3A (free) and Rapture 3D (expensive) plugins are excellent, also the free Facebook 360 Spatial Workstation software is very good and outputs to FB and YouTube formats. I mainly use these plugins with the Reaper DAW (Digital Audio Workstation) – it’s much more flexible than more well-established DAWs and inexpensive.
Q - Where do you suggest us amateur 360 sound recordists start?!
A - A great place to start is with the FB360 software – it’s free and can use ambisonic recordings, but it’s also really easy to pan mono sources to anywhere you want and export to common formats.
The ambisonic mics I mentioned are all good though expensive to start with but there are some cheaper alternatives arriving now that may be worth looking at.
The Zoom H3-VR is very very cheap (£300!) compared to pro ambisonic mics but would be perfect for lower budget binaural production when used with ambisonic to binaural plugins. Reaper would be my DAW of choice and there are a lot of useful tutorials for it online.
Q - Any recommendations of things we can listen to?
One of the most recent projects I worked on was the S3A Project, with the BBC and Universities of Salford, Surrey and Southampton. There we created a 3D audio drama called 'The Turning Forest' which won some awards recently, it was also released as a VR experience and the binaural audio works really well in it. You can find that on Google Daydream and Oculus sites (and below).
I’m currently working on another project with my company, Salsa Sound, to create binaural fan experiences for sport on mobile devices so watch this space for releases!
Q - Aside from podcasts - who else/where else is using binaural sound technology?
A - There’s some interesting experiments in radio drama using binaural, VR and 360 video is becoming a big deal so, for example, you could watch last year’s UEFA Champion’s League Final in 360 video with binaural audio... (Note from Clare: Who wouldn't want to watch THAT Gareth Bale overhead kick in 360!)
I fully expect augmented audio reality to take off over the next few years as well, there’s a lot of audio development activity in the ‘wearables’ sector, for example one of our Salford PhD graduates who is now at Apple recently published a patent for headphones with head tracking – that’s the kind of mass-market that will really drive audio AR. But gaming is probably the biggest market for binaural at the moment...
Thanks to Ben for his insight and speedy response. And if you didn't know, Salford Acoustics is the primary partner for acoustics research in the BBC Audio Research Partnership. The laboratories are a calibration and test house for construction, government, military, audio R&D and the motor industry. More about them and what they get up to here. You can read my previous posts on binaural sound here - interview with sound recordist Chris Watson, 3D audio producer Michel Delafrance and BBC R&D producer Tom Parnell.