5 Chapter 5: Sound for 360 Video
Sound can distract us or take us out of a moment. Poorly recorded, distorted, muffled sound is unpleasant for the ear and can ruin an otherwise great video experience. When the visuals don’t match what we’re hearing, it can be confusing. For 360 video, sound may be an even more important consideration than for other types of visual mediums because of the high level of presence we’re trying to generate. When the sound is recorded and produced well, your 360 audio content can go a long way to pulling your viewer in. Here we offer you some suggestions on achieving great sound for your projects.
The different types of audio formats
Without getting too technical for a beginner’s guide, when discussing audio, we’re usually referring to the five most common ways to record and listen to sound playback. There’s mono sound, which is recorded with one microphone and gives you one channel of audio (hence the use of term “mono,” which is Greek word for “alone” or “single”) You’re probably pretty familiar with stereo sound, which is recorded by spacing two microphones apart onto two channels (left ear and right ear). This is the most widely used format in the modern era.
Then, there’s a special kind of stereo recording called binaural audio. Like stereo, this is made by using two microphones, but the microphones are positioned on a dummy or a special configuration to better mimic how human ears are positioned. This helps to recreate the natural way we experience sound, with certain sounds registering at different volumes depending on their position of origin. The differences in binaural sound can be heard while using headphones and sounds more dynamic and realistic. This is where we start to get into the realm of “3D sound,” which has become something of an umbrella term for several immersive recording formats, including binaural.
The BBC has a video on YouTube that demonstrates how binaural sound works:
There’s also surround sound, which is most commonly available in the 5.1 format, but other formats exist, including 7.1 and Dolby Atmos. This type of sound works by recording with multiple microphones on several channels and then playing back each audio element through a different speaker. A 5.1 surround system, for example, would generally involve positioning six speakers (including a subwoofer) around the listener, like in movie theatres or scaled down home cinema setups. A 7.1 system connects with eight speakers. Increasingly, high end headphones are incorporating surround sound technology with several distinct speakers embedded into the speaker cups.
And finally, there are ambisonics, which utilize at least four microphones arranged in a tetrahedral configuration to record on multiple channels of audio. The key difference between ambisonics and surround sound is that the audio signals in surround sound are sent to distinct, designated speakers, whereas ambisonic audio signals are not preset to any particular output. This he