In the uncompressed situation I know I need to read the wav header, pull out the number of channels, bits, and sample rate and work it out from there: (channels) * (bits) *
In the .net framework there is a mediaplayer class:
http://msdn.microsoft.com/en-us/library/system.windows.media.mediaplayer_members.aspx
Here is an example:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2667714&SiteID=1&pageid=0#2685871