C＃DirectSound音量控制

Question

我进行语音聊天，但我无法控制音量和平移。当我控制音量时，它无效。

playbackBuffer = new SecondaryBuffer(playbackBufferDescription, device);
//playbackBuffer.Volume = 0; // -1000 ~ 0
//playbackBuffer.Pan = 0;
playbackBuffer.Write(0, byteDecodedData, LockFlag.None);
playbackBuffer.Play(0, BufferPlayFlags.Default);

怎么办？