The IDirectSoundBuffer::SetVolume method changes the volume of a sound buffer.
HRESULT SetVolume(
LONG lVolume
);
lVolume
New volume requested for this sound buffer.
If the method succeeds, the return value is DS_OK.
If the method fails, the return value may be one of the following error values:
DSERR_CONTROLUNAVAIL
DSERR_GENERIC
DSERR_INVALIDPARAM
DSERR_PRIOLEVELNEEDED
The volume is specified in hundredths of decibels (dB). Allowable values are between DSBVOLUME_MAX (no attenuation) and DSBVOLUME_MIN (silence). These values are currently defined in Dsound.h as 0 and -10,000 respectively. The value DSBVOLUME_MAX represents the original, unadjusted volume of the stream. The value DSBVOLUME_MIN indicates an audio volume attenuated by 100 dB, which, for all practical purposes, is silence. Currently DirectSound does not support amplification.
IDirectSoundBuffer, IDirectSoundBuffer::GetPan, IDirectSoundBuffer::GetVolume, IDirectSoundBuffer::SetPan