Microsoft DirectX 9.0

Environmental Reverberation

DirectX provides partial support for environmental reverberation in accordance with the Interactive 3-D Audio Level 2 (I3DL2) specification, published by the Interactive Audio Special Interest Group. The DirectX environmental reverb effect is an implementation of the listener properties in the I3DL2 specification. Source properties are not supported.

Sounds reaching the listener have three temporal components:

The combination of early reflections and late reverberation is sometimes called the room effect.

Note   In the DirectSound implementation, only the signal sent to the room effect is heard. To hear the direct path, play the sound simultaneously in another buffer that does not have the environmental reverb effect.

Reverberation properties include the following:

Reverb properties are represented by an IDirectSoundFXI3DL2Reverb8 interface, and the parameters of the environment are contained in a DSFXI3DL2Reverb structure.

DirectX supports many sets of default parameters, or presets, that describe the reverb properties of audio environments ranging from mountains to sewer pipes. Most applications can simply choose one of these environments by using IDirectSoundFXI3DL2Reverb8::SetPreset.

To set custom properties, use IDirectSoundFXI3DL2Reverb8::SetAllParameters. You can retrieve the current properties by using IDirectSoundFXI3DL2Reverb8::GetAllParameters.