Echo
[The feature associated with this page, DirectSound, is a legacy feature. It has been superseded by WASAPI and Audio Graphs. Media Casting have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Media Casting instead of DirectSound, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
An echo effect causes an entire sound to be repeated after a fixed delay.
This effect is represented by the IDirectSoundFXEcho8 interface. Its parameters are contained in the DSFXEcho structure.