Seriously, this is hardcore. In conversation with Mark Cerny, he laments that he gets to meet very few audio engineers on his regular visits to developers and publishers - and that for delivering a next generation audio experience, Sony itself had to take point. Audio itself has been fairly poorly served across the current generation, typically getting a fraction of a Jaguar core to deliver 7.1 surround - far less than audio enjoyed in the PS3 era, where the SPUs proved ideally suited to audio processing tasks. In fact, Cerny points to PSVR as a modern-day standard bearer of sorts for surround audio, as it features a bespoke audio unit capable of supporting "50 pretty decent sound sources". PlayStation 5's new Tempest Engine supports hundreds - delivered with a much higher quality.
It's all based around the key tenets of presence and locality. Cerny describes presence vividly. In games today, rain is a simple, single sound. With the Tempest Engine, PlayStation 5 aims to engender the feeling of actually being in the middle of the shower by simulating the sound of individual raindrops hitting the ground around you. Locality? This is more about being able to precisely track where objects are located - and the science in delivering this is simply astonishing, having to taken into account the shape of your ears and even the size and shape of your head.
To precisely simulate accurate positioning, Sony needs to generate a table called the Head-related Transfer Function - HRTF - ideally on a per-person basis. How you perceive audio can be simulated by processing the soundscape through that table - a computationally expensive task to say the least. The Tempest Engine is effectively a re-engineered AMD GPU compute unit, stripped of its caches and relying solely on DMA transfers - just like a PS3 SPU. In turn, this opens the door to full utilisation of the CU's vector units.
"Where we ended up is a unit with roughly the same SIMD power and bandwidth as all eight Jaguar cores in the PS4 combined," Mark Cerny reveals in his presentation. "If we were to use the same algorithms as PSVR, that's enough for something like five thousand sound sources - but of course we want to use more complex algorithms, and we don't need anything like that number of sounds."
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