|Microsoft DirectX 9.0|
A parametric equalizer amplifies or attenuates signals of a given frequency.
Parametric equalizer effects for different pitches can be applied in parallel by setting multiple instances of the GUID_DSFX_STANDARD_PARAMEQ effect on the same buffer. In this way, the application can have tone control similar to that provided by a hardware equalizer.
This effect is represented by the IDirectSoundFXParamEq8 interface. Its parameters are contained in the DSFXParamEq structure.