VS 2005 legacy DirectX

I have a legacy DirectX application that I would like to move from VS 6 to
VS 2005. I don't seem to find any articles or assistance on the web for
this kind of an adventure.
For instance it appears that streams.h has been replaced but I'm not certain
what to replace it with.

As I've inherited this app I'm having to learn the old DirectX audio classes
and I don't see them in the new .Net flavor of DirectX/DirectSound. Things
like CSourceStream and CBaseFilter to name two, just don't seem to be there.
Can anyone point me to some documentation that will help educate me on this
Thanks in advance for any assistance.