sending a beep through microphone input

Question

Is a way of creating a program (either in C(+,++,#) or VB.net) that would be able to send a beep sound through the same line-in that is being used for audacity (not stereo mix)?

I am trying to make a way of syncing up audio and video from 2 different programs, in a similar way that a clapper bored works in the movies.

Would there be a way of using a sort of microphone enhancement that could be created because they affect the microphone input?

Answer 1

I assume you're trying to implement something like http://www.singularsoftware.com/pluraleyes.html then? I think the best way would be to write a VST/LADSPA plug-in for Audacity that inserts the beeps synced to a timecode stream (or whatever you're syncing to).

There's a neat little library called VST.NET that allows you to write VST plug-ins in standard C#/VB.NET if you like.