| It is anticipated that 3-D sound will become a major component in virtual reality environments. In this thesis, we investigate the development of a Windows(TM) 3-D sound system using binaural technology. This work should eventually be integrated in complex virtual environment software. The 3-D sound effects are achieved by applying a filter pair representing audio cues from a specific point in space to the left and right channels of headphones. As a first step, an offline 3-D audio file generation system is developed, and effects such as sound reflections in a virtual rectangular room are added to this system. The real-time implementation is considered next. The first approach tested for the real-time implementation uses the time domain convolution of a sound source signal with head-related transfer functions, but the computational load of this approach is such that it cannot run in real-time at audio sampling rates. As an alternative, a second approach with a Fast Fourier Transform overlap and save technique is used to reduce the computational load, and a real-time implementation at audio frequencies is therefore successfully achieved. |
