Installing a fake microphone on Windows Server

Virtual Audio Cable should do what you need, including redirecting the playback of your wav file from a virtual speaker to your virtual microphone if desired: http://software.muzychenko.net/eng/vac.html

Microsoft publishes the source code for a Virtual Audio Driver as part of the Windows Driver Development Kit. If you have access to Visual Studio, or if you know a programmer who does, compiling this virtual driver and installing it on your EC2 instance may accomplish what you need.

Try this one. It has it's limitations like : "Local session only (not available from Remote Desktop)" "The trial is 100% functional, but you get an annoying message every few seconds saying it's a trial."

http://software.muzychenko.net/eng/vac.html