Throughout my recording and soundscape career, I've explored various (if not all!) recording methods to capture the sound worlds which surround us. However, binaural recording has always held a special place in my heart, since I read about it being used as a recording technique in Sound On Sound sometime in the mid-1990s about Tchad Blake .

The idea of a dummy head or headphone method was beyond my budget at that time, and of course this was pre-internet DIY advice. It wasn’t until a few years later when I was able to purchase a set of SoundMan OKM Classics (which I still use and have!) that my immersion into the world of binaural fully began. In this blog post, I'll share my insights and experiences with binaural recording, highlighting its unique advantages and addressing the challenges it presents, particularly when recording in public spaces.

Embracing Binaural Recording

Binaural recording resonates with me for several reasons, primarily the ease of set up, the size of the gear and the ability to be the invisible recordist in a space not interfering or influencing activity within the soundscape. Binaural recording for me, adds a sense of authenticity and presence to my recordings. Binaural recording also offers a ‘stealth’ approach to recording, and whilst this may sound a bit dodgy or like spying, my interest is about the sound environments, I have no interest or desire to capture conversations etc without consent (in fact I often wish people would just shut up in some places!!), rather I an interested in embracing the method's ability to provide an unobtrusive way to record authentic ambiences. I've found that using external microphones often attracts attention (usually unwanted) and disrupts the natural flow of spaces. Binaural recording, however, allows me to blend into the environment seamlessly, fostering genuine recordings.

The Essence of Binaural Recording

Neumann KU 100 Dummy Head — Neumann *KU 100 Dummy head*

Over the years, I've experimented with various different setups, including the Soundman OKM series, ORTF with Jecklin disc and ambisonic microphones, and more recently, the Sennheiser AMBEO headset and Immersive Soundscape Earsight Binaural Mics. I have also had the fortune to have access to the Neumann KU-100 (which is awesome) and inspired me to build my own DIY version (which is not too bad at all!) The SoundMan and AMBEO mics are my usual go to mics and are always in my bag with me, and have enabled me to exist within the sonic space without drawing undue attention.

When listened to through headphones, binaural recordings create an astonishing sense of depth, directionality, and realism. The personalisation of the recording experience through individual Head-Related Transfer Functions (HRTFs) is a significant advantage of binaural recordings, and while recordings tailored to one's HRTF are best enjoyed on headphones, the immersive experience can still captivate listeners who don't share the exact HRTF.

As technology continues to evolve, such as iPhone advancements in HRTF scanning, this will no doubt lead to better immersion for the listener.

*Sennheiser Ambeo HeadSet Binaural Microphones almost invisible*

Understanding Binaural Recording

Binaural recording mimics the way human ears perceive sound in a three-dimensional space, and comes from the Latin words "bi" (meaning two) and "auris" (meaning ear). Thus the requirement to record sound using two microphones placed to replicate the ear's position and filtering by the pinnae (ear lobe), along with many other acoustic parameters such as inter-aural time difference and phasing.

However, binaural can be approximated using a jecklin disk, or two relevantly spaced microphones with a block of something in the middle (see below).

Applications for Binaural Recording

Ambience and Soundscapes: This has been my main use for the technique over the years, as it is particularly effective for capturing ambient sounds and natural soundscapes, it is a lightweight solution and also discrete. As I always say to my students, I am not interested in covert recording at all, but this method enables me to record in spaces without being harassed or questioned. It also makes for a much more mobile recording set-up which is always present where I am. One of my favourite recordings was in a Museum in Amsterdam, where I was able to take in the art and record at the same time.
Soundscape Research: Binaural recording has been a favoured method for much soundscape research, again due to it’s immersive nature, cost and ability to capture without the method intruding into the study.
Soundscape archiving and preservation: The ease and ability to always be recording where ever you are, means that binaural is a great way of capturing an environment for heritage archiving. For example, capturing sound-walks in a city, mean that you are able to walk for hours taking in many different aspects of the soundscape, each valuable in it’s own way.
ASMR (or Autonomous Sensory Meridian Response): As binaural recordings can create intimate and spatial recording, they are an ideal method for capturing whispers, tapping, and other delicate sounds that trigger a tingling sensation in listeners in 360 space.
Events: Binaural recording offers opportunity to relive a live event (or performance perhaps, which is an ethical question)and transports listeners right back into the time and place, capturing the energy and spaciousness of the event. I have captured many protests, and public events, such as the 2012 Olympic Torch procession, Stop the war marches, football rampages and 2023 Kings Coronation being present in the crowds.
Studio Recording: whilst not necessarily a widely used technique, it can in interesting to capture recordings and performances binaural, especially given how much music is consumed on headphones these days. From a piano recording from the player’s perspective, to the sound of drums in a room. Sticking up a dummy head can give your another option for your mix.
Virtual Reality (VR) and Gaming: Obviously it is a natural fit for VR and gaming experiences, enhancing the sense of presence and immersion, and I believe we will be seeing much binaural applications within the digital gaming space, heightening the overall realism.

Binaural Recording Methods

Typically, omnidirectional microphones are used, with a capsule placed inside a real or simulated ear (and perhaps in an anthropomorphic head). The microphones are positioned in or as close to the ear canal and spaced around 7 inches apart, thus recreating the average distance between human ears.

In a nutshell, that is pretty much it when it comes to microphone placement, the rest of the technique is overcoming problems that occur during recordings. In particular:

Be careful with the microphone cable if you are wearing them in your ears, especially if recording soundwalks, as the cable can and will generate it’s own noise. This is usually from banging against your body, your head or just itself. I usually thread the cable down my top to prevent this as much as possible.
In addition, if you have any zips or items on your clothes which create their own sound (bag zips, buttons, rustly fabric are the worse offenders here, either change into something else or find a wat of dampening them. Best thing to do (as always) is test the set up before you start recording or go out into the field.
If you are using binaural as a method to record soundwalks, remember that you may need to consider how you walk, your shoes, how and where you place your feet and may need to tread lightly or tip toe in quieter places to avoid picking up your footsteps. This is actually quite a nice meditative zen practice, of light walking, preempting the world and sensing how your foot makes contact with the earth and what kind of sound it may make.
Self noise, note no matter how hard you try, at some point you will invariably sneeze, cough or make a strange sound….don’t forget to edit it out. This can’t be avoid, but you can sometimes preempt a sneeze and try to contain it until there is a good time to pause your recorder.
Head movement, if you move your head you are changing the perspective for the listener. Consider if this is something that you want or don’t want in your recording. For example, do you want to hear the police siren pass by in one ear, or do you want the recording to capture you moving your head to follow it. Both are valid, but require consideration as to how the apply to your recording method.

Documenting with cameras.

If you are documenting your walk with a camera, especially a DSLR style camera, remember that any shutter clicks and lens auto focusing will be picked up by the binaural mics. Either disable this (if you want or can), try using a camera phone with no shutter sound (but this increases self movement). Ideally, come back to do your photography. One job at a time, and this allows you to be more present in the recording process and moment.

Wind - the biggest problem of all…

When recording outdoors, wind noise can be a major challenge regardless of the technique employed, and mitigating it one of the biggest challenges. Windscreens, blimps, or specialised protection can sometimes minimise the impact of wind on the microphone capsules, but unlike traditional microphones, with binaural recording placing tor mounting these can often be difficult (or look very strange). To mitigate wind noise, I've found success in using various weights of beanie hats or cloth hats that can be pulled over the ears. Although this approach might attenuate high frequencies slightly, it significantly reduces wind interference. Alternatively, one can repurpose broken open-back headphones as microphone casings, providing both protection and a natural appearance.

Dancing with the Wind

When recording in windy environments, it's crucial to attune yourself to the wind's patterns. Much like a bird navigating currents, you'll need to sense the wind's movements and adjust your head positioning accordingly. By identifying wind vortexes, often around building corners or surfaces, you can position yourself to minimize wind interference. Walking towards the center of a street when near buildings or gently moving your head in and out can help you "surf" the wind currents and maintain clear recordings.

Alternative Recording Methods

Binaural with a bag

binaural field recording alternative method with a bag — *Binaural field recording: alternative method with a backpack*

Whilst not strictly ‘binaural’, recording with omni microphones strapped to the side of a bag can be extremely effective, with the bag acting as a proxy head. Simple clip two omni microphones to the side of a backpack and go record.

Glasses

You can create a binaural recording by clipping microphones to your glasses or sunglasses, still not technically binaural as the pinnae filtering is missing, but your head is creating all the relevant time differences and works really well.

Tree ears

Taping or clipping your omnidirectional microphones to either side of a tree bark once again can create and interesting and engaging spactial effect, with the tree acting as a proxy head. The closer to a diameter of 7 inches will give more realistic results, but actually going much wider can produce a very spacious and enaging recording,especially when played back over a headphones. There will be a hole in the middle of the soundfield if you go too wide, but for capturing large, wide ambiences where you are not concerned about a single element, this method is extremely effective.

DIY Dummy head

It can be very cheap and easy to construct your own dummy head, without the need to splash out over £8k for the Neumann KU-100! I will write a separate article on ‘Building a DIY binaural head for less than £15’, coming soon.

Listening back

Listening to binaural recordings through headphones can be an amazing and immersive experience. The soundscape emanates from all around, creating an illusion of being physically present in the environment. Often taking you back to the recording moment (if you were the recordist), helping fi yourClose your eyes, and you can almost feel the wind rustling through leaves, footsteps echoing in an alley, or raindrops falling from above.

The Mindful Connection

Binaural field recording opens a portal to an auditory dimension that is as real as it gets. Its techniques and methods transform the act of listening into an enchanting journey through space and time. Whether it's for capturing nature's symphony, ASMR whispers, or the grandeur of live performances, binaural recording pushes the boundaries of sound and storytelling. So, grab your headphones and embark on an adventure of sound that will leave you marveling at the art of recording.

Recording using binaural techniques in public spaces is a mindful endeavor. As you become attuned to the wind and your surroundings, you'll develop an intimate connection with the environment. This mindful approach not only enhances your recordings but also creates a sense of harmony between you, the space, and the soundscape. Through patience and practice, you can master the art of being present in the moment while capturing the essence of your surroundings.

In conclusion, binaural recording holds a unique allure for those seeking authentic, immersive soundscapes. While wind noise and the challenges of recording in public spaces may seem daunting, creative solutions and a mindful approach can lead to exceptional results. As technology continues to evolve, such as iPhone advancements in HRTF scanning, the future of binaural recording looks promising. So, whether you're an audio enthusiast or a field recording artist, embrace the world of binaural recording, and let the sonic landscape speak to your heart and ears in its purest form.

Peace

Neil