Valve today released a new tool called Steam Audio that represents the fruit of its purchase of Impulsonic in January. The tech promises sound which very realistically responds to a virtual environment and would serve as an improvement over the standard 3D audio.
In the demo video below you can hear the audio change as a player moves around a virtual room. In particular, some of the sound is partially blocked by a wall, altering the pitch and volume more than normal.
It is a pretty sparse example, but when applied to VR you would have sound that more realistically matches your actions and behavior. Crouching to hide underneath a desk as an alien creeps nearby takes on new meaning when the creature’s steps sound slightly different depending how much of the desk is blocking or reflecting the sound before it hits your ears. 
From the Steam Audio page:
Reflections and reverb can add a lot to spatial audio. Steam Audio uses the actual scene geometry to simulate reverb. This lets users sense the scene around them through subtle sound cues, an important addition to VR audio. This physics-based reverb can handle many important scenarios that don’t easily fit within a simple box-model.
Steam Audio applies physics-based reverb by simulating how sound bounces off of the different objects in the scene, based on their acoustic material properties (a carpet doesn’t reflect as much sound as a large pane of glass, for example). Simulations can run in real-time, so the reverb can respond easily to design changes. Add furniture to a room, or change a wall from brick to drywall, and you can hear the difference.
The tech supports PC, Mac, Linux and Android. It is launching with Unity integration but Unreal Engine 4 support is coming soon with other software integrations planned as well.
