PlayStation 4 lead architect Mark Cerny is always eager to talk about the hardware inside the PlayStation 4. He recently revealed that the PlayStation 4 has a dedicated audio processing chip, which is used to compress and decompress audio streams and various formats. This frees up some of the CPU power for other tasks.
The custom audio chip in the PlayStation 4 also deals with the voice chat system. However, the main sound and audio in the game, such as effects etc, is processed by the GPU. The GPU has general purpose cores, which can be used for physics, audio, and other aspects of the game.
The PlayStation 4 features an AMD GPU with 18 compute units, which is 50% more powerful on paper than the GPU found in the Xbox One, which only has 12 compute units.
Recently, Cerny gave an in-depth presentation about how the PlayStation 4 was created, and compared it to previous PlayStation consoles.