What Is Binaural Recording - And Why I Don't Always Do It

Binaural Diaries began, as the name suggests, as a collection of binaural field recordings. It's been the foundation of the project since I started back in 2006, and it remains something I return to whenever I can. But over the years, the site has grown to include all sorts of captures — conventional stereo, ambient recordings, contact microphone experiments, hydrophone dips into rivers — and I thought it was worth writing about why that shift happened, and why binaural, despite being the technique that gave this whole endeavour its name, isn't always the one I reach for.

What binaural recording actually is

Put simply, binaural recording captures sound the way your ears hear it. Two microphones are positioned to mimic human ears — either mounted in a dummy head or, more practically for someone wandering about, tucked into the recordist's own ears using in-ear binaural microphones.

The reason it works is down to physics. Your head, your ear canals, the shape of your pinnae — all of these subtly alter incoming sound before it reaches your inner ear. They create tiny timing differences between left and right, level differences, and frequency colouration that your brain instinctively decodes as spatial information. Binaural microphones placed in the ear pick up all of this naturally.

Played back on headphones, the result can be remarkably immersive. Sounds appear to come from specific directions — to your left, behind you, above you. A bird calls from one side, a car passes left to right, a church bell rings in the distance. It's the closest audio equivalent to a photograph: a faithful capture of what it actually sounded like to stand there and listen. It's why I've sometimes called these recordings "sound photographs."

Over the years I've used a few different binaural setups:

Why it's worth the effort

When conditions are right, binaural recording produces something that conventional stereo simply can't. A standard XY pair on a portable recorder gives you a perfectly listenable stereo image, but it doesn't place you in the space in the same way. There's a transportive quality to a good binaural recording that I've not found anywhere else.

Recording the train journey from Bristol to Severn Beach binaurally, I could hear not just the carriage sounds but the way they moved around me — announcements echoing from specific points, the clatter of the track shifting subtly as the train rounded curves. Listening back, I was back on that train.

And then there's the weather

The trouble is, binaural recording — particularly the in-ear kind — is spectacularly vulnerable to the elements.

Wind is the obvious culprit. In-ear binaural microphones sit exposed, protruding from your ear canals. Even a gentle breeze, the sort you'd barely register walking down the street, translates into a low rumble and thudding on the recording that's utterly destructive. It's not a subtle degradation. It ruins things completely and irrevocably.

Wind protection helps, up to a point. Foam windscreens take the edge off slightly, but often impair the ability to seat the mics in-ear, and come at the expense of stealth. Anything beyond a light breeze they're fighting a losing battle. On a properly blustery day, there's simply no way to get a clean binaural take outdoors.

The built-in mics: always ready, better protected

This is where the built-in microphones on portable recorders earn their keep.

Both my Sony PCM-M10 and the newer Tascam Portacapture x6 have built-in XY stereo microphones. They're permanently attached, always ready to go, and - crucially - can be significantly better protected from wind than bare in-ear binaural mics.

A wide range of foam and fur windshields, from budget to premium are available from a variety of manufacturers, and designed to fit specific recorders. Add one of these and you've got a setup that can handle conditions that would render binaural recordings unusable.

I've used the built-in mics on countless recordings over the years. The Boxing Day birdsong at Lydbrook, the thunderstorm in France, the acoustics of the "Our Colour" installation at Cabot Circus — all captured on the PCM-M10's built-in mics. The Cabot Circus recordings, made in a concrete multi-storey car park, benefited enormously from the protection the housing provides, even indoors where air movement from doors and ventilation would have caused problems for more exposed mics.

The trade-off is clear: you lose the immersive three-dimensional spatiality of binaural. XY stereo gives you a fine, listenable image, but it won't transport you into the space in the same way. However — and this is the heart of the matter — a clean, well-captured stereo recording of a beautiful location is far, far better than a binaural recording destroyed by wind noise. A recording you actually managed to make is worth more than a perfect technique you couldn't deploy because the weather wouldn't cooperate.

Sometimes speed is essential

There's also the practical consideration of time. In-ear binaural mics require careful insertion, a cable run to the recorder, and ideally some level monitoring. When you hear something wonderful and fleeting — a hot air balloon drifting over the neighbourhood and setting off every dog within earshot, for instance — you need to hit Record now, not in three minutes after wiring yourself up.

The built-in mics eliminate that friction. Pick up the recorder, press record, and you're capturing. There's enormous value in that readiness. The local dog population went into overdrive as those balloons passed overhead, and I would have missed it entirely if I'd needed to set up binaural mics first.

Other options, other worlds

It's worth noting that I also use microphones that sidestep the weather problem entirely. Contact microphones — like the JrF C Series Pro+ — pick up vibrations through solid surfaces rather than through air, so wind is irrelevant. Hydrophones — like the JrF D Series+ — work underwater, immune to anything the sky is doing. These open up entirely different sonic territories, and in a sense, they've shown me that there are rich soundscapes to be captured regardless of the conditions above ground.

The Clippy EM172 stereo pair is another versatile option that can be arranged in various configurations spaced omni, ORTF, near-coincident - giving me something between the intimacy of binaural and the robustness of built-in mics, depending on the situation. Attaching these to Clippy lyre stand mounts from Micbooster.com, with a stereo bar and tripod create a versatile and adjustable rig.

Pragmatism

Nearly twenty years of doing this — with a sizeable gap in the middle for parenting and work demands — has taught me that the most important thing is to record. To get out there, capture something, and share it. The technique matters, of course it does, but obsessing over method at the expense of actually pressing the button is a trap.

Binaural is brilliant when conditions allow. Calm days, sheltered spots, quiet environments, and sessions where I have the luxury of time — these are where it shines. The train journey to Severn Beach, the early morning birdsong inspired by International Dawn Chorus Day, the French rural ambience on a still evening. When the conditions align, nothing else comes close.

But the built-in mics are always there, always ready, and well-enough protected to deliver usable results when the wind picks up, when rain threatens, or when I've got thirty seconds before the moment passes.

The thread running through Binaural Diaries has never really been about a single recording technique. It's curiosity about the sounds that surround us every day — and that curiosity is best served by having options and knowing when each one fits. Keep the binaural mics for calm days and special occasions. Keep the built-in mics for everything else. And keep recording, whatever the weather decides to do.