4. Software libraries for spatial sound rendering

Some of the spatial sound restitution techniques described here are implemented in various publicly available software libraries, which can provide a good starting point for integrating spatialized sound into a virtual reality application. For example, DirectSound, the audio component of Microsoft's DirectX library, provides support for spatialized sound on speakers or headphones. The beauty of this library is that its functions are hardware-accelerated, and are supported by the vast majority of sound cards (especially consumer ones). However, the library's specifications do not impose a predefined algorithm for sound spatialization itself, the quality of which is therefore vendor-dependent. What's more, the library is limited to a single platform, MS Windows. To address this limitation, an alternative, OpenAL, has been developed mainly by sound card manufacturer Creative. OpenAL incorporates...