Our love of audio, whether it be music, movies or games, is nothing new. Audio has evolved from early stereo to cutting-edge surround sound, and sophisticated home theaters and premium audio equipment are being developed.

But the world of audio is always extremely subjective. What sounds harmonious to one person may sound unpleasant to another, while someone is captivated by deep bass and someone else is captivated by clear highs. Not only that, the equalizer settings that sounded perfect last time may need to be adjusted the next time you listen, even if it's the same person listening.

With the advent of surround sound, the problem has become more complicated. From 5.1 systems to 7.1 and then 9.1, the number of speakers, woofers, and tweeters continues to increase in the pursuit of auditory perfection. And just when you think you have it all, along comes innovations like Dolby Atmos and DTS. These techniques added dimensions such as height to existing combinations.

Of all these advancements, spatial audio is expected to be the game changer of the future. Spatial audio enables a personalized audio experience rather than a one-size-fits-all approach.

A detailed 3D scan of the listener’s head is taken to create a unique audio profile that takes into account not just the distance and shape of the ears, but also hearing sensitivity. An in-ear microphone detects the listener’s unique Masimo sensitivity.

This is how our ears respond to certain frequencies. Add anatomical data to this. The result is an audio stream tailored to each individual, enabling an immersive listening experience like never before.

■ How does spatial sound enhance immersion?

The key to making spatial audio experiences truly immersive is head tracking. In real life, we hear different sounds coming from different directions depending on how we turn our heads.

Spatial audio aims to mimic realistic, lifelike sound. But there’s a problem: How does an audio processing engine know where a person’s head is pointed in a home theater environment?

This feature requires more technologies on top of existing ones. For this tracking, a video camera can be used to track where your head is pointed while you watch a movie.

Alternatively, you could tether your smartphone to your head using a cord and track your head using the accelerometer and gyroscope.

Alternatively, everyone in the theater could wear a VR headset that supports head tracking and spatial audio (Figure 1).


Several smartphone manufacturers are implementing spatial audio processing into their phones, and operating systems are supporting this approach. This may work, but it won't be as good as tracking head position using precise data.

Immersive gaming is now adopting this head-tracking approach, using precise data to achieve more immersive experiences. When you put on a VR headset, the VR software knows where your head is pointing, so it updates the screen to reflect the direction you are looking. Depending on what you are looking at, the sound will also be heard from that perspective.

In this regard, gaming will act as a catalyst for advancing this technology. Above all, gaming has a wider base than any other application (as of now). Also, gaming software companies will be quick to adopt this technology, as gamers are always looking for a more immersive experience. In addition, gaming consoles have the processing power needed to implement spatial audio and the memory/storage capacity to store spherical audio tracks.

■ Future possibilities

In the near future, earbuds will not only have built-in microphones, but also accelerometers and high-speed two-way wireless communication, allowing spatial audio to be used in other markets as well. This will allow, for example, a listener to turn their head and hear the woodwind, brass and string sections more clearly depending on which direction they are looking while listening to a symphony orchestra performance in their home theater.

The military can also use this technology. It can be used with advanced directional audio microphones to detect enemies in forests, deserts, or other hidden environments, for example. By filtering and detecting breathing and heartbeats, soldiers can turn their heads to find targets.

■ Conclusion

We are entering an era where audio can be as personalized as a fingerprint. There are challenges to overcome to get there. Spatial audio is what enables hyper-personalization, and it requires precise head tracking. This requires increasingly sophisticated technologies. Gaming is currently the most widely used application, and other areas such as home theater and military applications will follow.

Right now, we'll see things like VR headsets and earbuds with built-in accelerometers, but as time goes on, we'll be able to experience auditory experiences that aren't just heard, but also felt with touch. This will open another new chapter in audio technology. We will listen, immerse, adapt, and evolve. Just as sound is infinite, so is our quest for the ultimate listening experience. This quest will push us toward new possibilities.

※ writing
Jon Gabay studied electrical engineering and worked as a design engineer, firmware coder, systems designer, researcher, and product developer for defense, commercial, industrial, consumer, energy, and medical companies. As an alternative energy researcher and inventor, he founded and ran Dedicated Devices, a company focused on automation technologies, until 2004. Since then, he has been dedicated to R&D, writing articles, and inventing technologies for the next generation of engineers and students.