The big standout news from today's PlayStation 5 technical presentation revolved around harddrive space, load times, and GPU power, but Sony's system architect Mark Cerny also dedicated some time to what may prove to be the new console's most transportive feature in the long run: it's audio capability.
On today's stream and in conversation with Digital Foundry, Cerny discussed the PS5's new approach to 3D audio with the Tempest Engine. In a nutshell, the Tempest Engine will let the PS5 deliver more unique sound sources simultaneously, all at a higher fidelity. The example Digital Foundry presents is the sound of rain. In a current generation game, most studios would opt to use the limited sound channels and processing capabilities at their disposal to have one general rainshower sound playing. But with the PS5, you could simulate the sounds of individual raindrops.
To really create a sense of presence, especially with simple stereo headphones on, Sony will need more than just the capability for more audio. For that, Tempest will use Head-related Transfer Functions, or HRTFs. An HRTF takes into account the shape and size of your ears and head to mix the audio in such a way that it sounds like it would if your body was in the game world. It seems like a fitting comparison would be the differences between listening to audio recorded on a simple stereo microphone, listening to audio recorded with a binaural microphone with two silicone ear covers (like those used by YouTube ASMR creators), and actually hearing sounds live in-person with your own ears.
"When using headphones and my HRTF, I occasionally get fooled and even think a sound is coming from the real world when it's actually coming from the game," Cerny says.
Processing an HRTF is not easy, so the Tempest Engine is "effectively a re-engineered AMD GPU compute unit" with about the same power as all the cores in a PS4. Sony is planning to launch the PS5 with profiles for five different HRTF settings at launch, but there's the possibility that players might be able to customize their HRTF down the line, perhaps by taking photos or video to let the console analyze their ear and head shapes. Sony already does a process like this for its headphone products that support "360 Reality Audio," so there's presumably some tech overlap there that could be applied to the PS5 down the road.
Microsoft also wants the Xbox Series X to deliver advancements in game audio. The Series X will also have its own dedicated audio chip, and as Xbox Director of Program Management Jason Ronald recently revealed on an episode of Major Nelson Radio, the Series X will also let developers use its dedicated ray tracing hardware for "things like spatial audio."
Cerny also says that he hopes the Tempest Engine improvements will be noticeable for players using conventional speakers and virtual surround sound systems. Still, saying the PS5 will deliver such a huge leap forward with basic stereo headphones—no upgrade required—right out of the box is a pretty big claim. Hopefully it pans out, especially if we'll be throwing down hundreds of dollars to expand the PS5's storage space.