Audio: still the most emotive communication channel

From the morning dawn chorus to directional audio and Dolby Atmos, David Shapton on the crucial role audio plays in our lives.

If you live away from a city in a temperate part of the northern hemisphere, you must surely have heard your local version of the dawn chorus, and if you have, you'll know there's much more to it than merely a curtain of birdsong. The audible awakening of our feathered friends is remarkable as much for the silence that precedes it as the joyful cloud of avian chirping. Sound is all about contrasts, and there are few as great as the transition from pure silence to what sounds like the cacophony of every living thing shouting for miles around.

Why is it so emotive? Is it because it represents a new start? Or life itself? Or is it just because it wakes us up? There's more to it than that. There's nothing more disorienting than arriving home after a late night, just at the start of the birdsong. For me, it's an instruction to forget about going to bed, because a new day has started.

Remarkably for such a profound and all-embracing experience, you don't need your eyes open to appreciate it. It might be that sound is an even more immersing and engaging experience than vision.

Nobody would choose to watch a film with the images switched off - it's a visual art form. But it's all too easy to underestimate the effect that good audio can - and almost certainly does - play in a film.

The wrong audio for The Wrong Trousers

I discovered this through a powerful lesson. I was installing an early digital audio workstation at a dubbing theatre in West London and training the talented sound editor to use the system. The film was Nick Parkes' The Wrong Trousers, a stop-motion animation involving Parkes' characters Wallace, a gangly, gormless but lovable inventor, and his sentient, helpful and long-suffering dog, Grommit. The short film premiered on UK national TV and was hugely successful. What I never thought about until I got involved was that when you're shooting stop-motion, there is no audio. Nothing. Plasticine characters can't talk, and the action is recorded hundreds of times slower than real-time.

I watched the famous train chase without sound, and it was funny. Weeks later, I saw it fully edited and dubbed. This time, it was hilarious, and the audio made the difference.

Audio is an analogue phenomenon. It has been since the dawn of time, and on a geological scale, it's only been picoseconds since the digital audio era started. But digital audio is only ever in the service of its analogue counterpart: as long as our ears are analogue, we're dealing with molecules in motion, not digits. Recording audio is all about the room: the surfaces, the angles, and the distances.

Talk close to the mic, and you get a big, dry sound. Move further back, and you record the room as well. This can add to a "finished" sound for choral, instrumental and orchestral works. Check out Allegri Miserere, sung by the King's College Choir below.

For interviews and dialogue, acoustics can be a help or a hindrance because of one thing: intelligibility. If you can't hear what people are saying, then you have, literally, lost the plot. (Also check out Interstellar for an example. I watched the film on a transatlantic flight and missed swathes of crucial dialogue.)

Overlapping roles

So you can see that audio plays multiple roles, often overlapping. It is both a scene-setter and a communication channel. It's a powerful emotional language, perhaps the most powerful. Sometimes it can seem like, because instrumental music doesn't use words, it can only ever express vague notions about emotions. I think the opposite is the case. To me, music is far more specific than words can ever be. If you can't name the emotion evoked by a piece of music, it's because it's so precise and accurate that it falls into the gaps between the meanings of existing words.

And now, we have directional audio. It's evolved from the original idea of stereo. In a way, stereo is the purest way to record and reproduce music. It opens up the stage without necessarily needing any production decisions. This doesn't apply so much to studio recordings where the panning of individual channels or voices is under the producer's purview, but even then, playing back the recording merely requires two amplifiers and two suitably placed loudspeakers.

Today's multi-channel spacial audio is a technological wonder. Dolby Atmos is staggeringly effective. It's not the first spacial audio system by any means, but it's widely adopted, it's becoming well understood in the industry, and you can even buy single-box Atmos-compatible speakers like the new Sonos Era 300.

Sound is at the centre of relatively new media forms like podcasts. As the genre matures, podcasters are buying better microphones, some designed to be easy to use (with USB computer interfaces eliminating the need for a separate pre-amp, mixer and audio I/O) and to give excellent results with the spoken word.

All ends of the audible spectrum

It's easy to forget - or perhaps never even realise - that sound is a self-sufficient, complete world with infinite nuances and unending subtlety. It can range from brutal and threatening to soft and comforting. We now have access to 32-bit recording to accurately capture anything from a feather landing on a duvet to a nuclear explosion (please understand that I'm being hyperbolic here...).

What I find most remarkable is that a loudspeaker cone that can only be in one place at one time can reproduce the sound of an orchestra, a cathedral choir, or an entire, complex film score. It works because of time: an extra dimension. It's how the loudspeaker moves that determines what we hear. If you try to freeze-frame audio, it disappears. It's constantly changing. In a sense, sound is an emergent property of time itself.