Three-Dimensional Sound

DirectSound enables an application to change the apparent position of a sound source, by using the IDirectSound3DBuffer and IDirectSound3DListener interfaces. Sound sources can be a point from which sounds radiate in all directions or a cone outside which sounds are attenuated. Applications can also modify sounds using Doppler shift. Although these effects are audible using standard loudspeakers, they are more obvious and compelling when the user wears headphones.

The following topics are discussed in this overview of 3D sound:

·Perception of Sound Positions

·Listeners

·Sound Cones

·Minimum and Maximum Distances

·Position Versus Velocity

·Integration with Direct3D

·Units of Measure and Distance Factors

·Mono and Stereo Sources