Hearing is an important sense for VR and has been unfortunately neglected up until this chapter. Developers of VR systems tend to focus mainly on the vision part because it is our strongest sense; however, the audio component of VR is powerful and the technology exists to bring high fidelity audio experiences into VR. In the real world, audio is crucial to art, entertainment, and oral communication. As mentioned in Section 2.1, audio recording and reproduction can be considered as a VR experience by itself, with both a CAVE-like version (surround sound) and a headset version (wearing headphones). When combined consistently with the visual component, audio helps provide a compelling and comfortable VR experience.
Each section of this chapter is the auditory (or audio) complement to one of Chapters 4 through 7. The progression again goes from physics to physiology, and then from perception to rendering. Section 11.1 explains the physics of sound in terms of waves, propagation, and frequency analysis. Section 11.2 describes the parts of the human ear and their function. This naturally leads to auditory perception, which is the subject of Section 11.3. Section 11.4 concludes by presenting auditory rendering, which can produce sounds synthetically from models or reproduce captured sounds. When reading these sections, it is important to keep in mind the visual counterpart of each subject. The similarities make it easier to quickly understand and the differences lead to unusual engineering solutions.