The environmental audio extensions (or EAX) are a number of digital signal processing presets for audio, present in Creative Labs later Sound Blaster sound cards and the Creative Nomad product line.

Environment perception

The aim of EAX is to create more ambience with 3D sound in games. This is accomplished due to simple HRTF functions for discrete sound, and a global environmental reverb effect. Newer versions of EAX added multiple reverbs to be applied simultaneously with smooth transitions between. EAX 4 HD is rumoured to allow sounds to be reflected discretely, similar to A3D's advanced wavetracing technology.