mciSendString('set all audio all on', nil, 0, Handle);
{立体声}
mciSendString('set all audio all off', nil, 0, Handle);
mciSendString('set all audio left on', nil, 0, Handle);
{左声道}
mciSendString('set all audio all off', nil, 0, Handle);
mciSendString('set all audio rigth on', nil, 0, Handle);
{右声道}