DirectSound 3-D Listeners

A sound is only a sound when it is heard. The 3-D sound effects in a DirectSound application are affected not only by the position, orientation, and velocity of the sound buffer, but also by the position, orientation, and velocity of the listener.

The IDirectSound3DListener interface controls the listener's position, orientation, and apparent velocity in 3-D space. It also controls the general parameters of the acoustic environment, such as the amount of Doppler shift and the rate of volume attenuation over distance.

This section describes how your application can obtain a pointer to an IDirectSound3DListener interface and manage listener parameters by using interface methods. The following topics are discussed:

• Obtaining the IDirectSound3DListener Interface
• Batch Parameters for IDirectSound3DListener
• Deferred Settings
• Distance Factor
• Listener Orientation
• Listener Position and Velocity
• Doppler Factor
• Rolloff Factor