It’s no secret that David Attenborough documentaries such as Planet Earth III and Dynasties use some of the most cutting-edge technology on the market, capturing natural spectacles that leave audiences (myself included) in floods of tears.  

The latest project from Humble Bee Films and Infield Fly Productions, featuring the revered presenter, puts this equipment at the forefront.  

Secret World of Sound, debuting on Sky Nature and this weekend, explores how animals communicate through their noises and how this influences their behaviour. The mini-series uses organic sound recorded at the time of filming, a change from many nature documentaries which add audio effects from an existing library in post-production. 

I got a first look at the debut episode, Hunters and Hunted, which delves into how sound is crucial to the survival of both predator and prey. The other two episodes in the series, Love and Rivals and Finding a Voice, examine the role of sound in mating and growth respectively.  

The cameras and microphones used in this documentary can capture audio that cannot be heard by human ears – either because it’s too quiet, or beyond our frequency range. Some microphones were physically designed to blend in with complicated environments. For example, the team used one that was the size of a little fingernail, so it could squeeze inside a beehive. 

Series Producer Sharmila Choudhury revealed in a press release that the team adapted two pieces of gear that hadn’t been used in nature documentaries before. The first is an acoustic camera, which is surrounded by up to sixty microphones. Traditionally, it’s key for determining the location of gas leaks.  

Chodhury explained why this technology is so useful for filmmakers: “…the microphones impose a kind of thermal image onto the camera and show you with a red hot dot where the sound is coming from. As you get further away from the sound, the colours change. We thought that would be good for trying to find animals using sound that we can’t normally hear or locate”. 

Secret World of Sound uses these acoustic cameras numerous times. In one behind-the-scenes snippet, we saw an expert discover the exact intricacies of how a great grey owl manages to suss out its prey beneath the snow by what it can hear, and why it often misses its catch due to the environment making the movements sound as if they’re in another place entirely.  

One other interesting piece of equipment used in this series is a laser vibrometer, which was originally developed for surveillance, such as when agents try to listen in on a conversation. However, the Humble Bee Films team did some spying of their own by utilising this tech to understand how insects communicate through vibrations.  

This is a perfect example of the documentary highlighting how animals use more than just their ears to communicate via sound. Elephants can sense the vibrations of a storm from hundreds of miles away by using special sensors in their feet, so the audio travels up their body and into the bones in their ears.  

We see a herd using this technique to chase the rain, so they can find sustenance during an unforgivable drought, which happened because of climate change – several years ago, their environments would have been filled with plenty of plants and water. 

Climate change is something Sir David Attenborough, aged 97, has continued to raise awareness of throughout his career. He gets on camera for this documentary once again to spread the message and advocate for change. His tone is articulate as ever and he has that playful wit in funny segments that fans have grown to love. One later episode in the series also shows him getting up close and personal with an animal, just as he’s done many times before.  

One element that is less prominent than usual compared to other series is music. In the Planet Earth series, legendary composer Hans Zimmer created emotional and movie-worthy scores. However, the team wanted the real sound to do the talking this time. The debut episode opens with the haunting roars of lions across savannah, for example.  

In a Q&A after the screening, Choudhury said the following: “…music is important, but we wanted to use it as little as possible, and wherever we could we let the natural sounds play out. Both in terms of the environment…and the animal sounds themselves.” 

This adds an extra level of immersion for audiences, as you feel amongst the wildlife as you’re watching. Of course, music isn’t gone completely, as Producer/Director Gemma Brandt explains: “We had a brilliant composer, Suad Bushnaq… the music we used very much works because it can help give an emotional cue. 

“The subject matter I was dealing with in my episode – mating – is always quite amusing so when I did put some music in, I wanted a bit of that comedy to come through because, you know, sex in the natural world can be funny.” 

As a tech writer, it’s fascinating to witness how Secret World of Sound utilises equipment from other industries to make discoveries about our natural world, and I’m sure any other gadget enthusiasts reading along will agree. At three episodes long, it’s a short commitment. Nonetheless, you’ll certainly learn a lot whilst enjoying stunning visuals and spellbinding sounds.  

Also, it’s probably worth mentioning – whilst episode one has a particularly brutal night-hunt scene, there weren’t any emotionally traumatising moments with cute baby animals as you might be expecting… though I can’t make any promises about episodes two and three.  

You can watch all three episodes in the Secret World of Sound on Sky Nature and Now from 25 February 2024 – no US release date has yet been announced. You can get the channel either via Sky Q, Sky Glass or Sky Stream, or sign up for for £9.99 per month.  

The best way to experience Secret World of Sound is with speakers that support 360-Dolby Atmos Sound, which you can get with the help of a soundbar from the likes of Sonos, Denon and Bose.