I'm afraid that you're probably facing a rather fundamental problem there. I was going to suggest sending the data to stdout, and piping it to something like 'netcat' (in Linux -- probably some equivalent in Windows), but I did some investigating first. (:-/)

The problem is that formats like WAV and AIFF are all chunked (R)IFF-style files, which begin with a header giving the overall size of the file. As a result, the data has to be written non-linearly. A dummy header is written first, then all the audio, and as a last step the program goes back to write the header properly (by repositioning in the file). Consequently you can't really stream the data through a pipe: any repositioning just closes the pipe (at least on Linux). In fact, the result seems to be that no data gets actually sent at all!

If you use the '-h' flag to Csound, to suppress headers, it will pipe fine, but it's no longer a WAV file then! (The Csound 'format' BTW is just a stream of values at the sample rate, presumably in either float or double depending on the Csound version.)

Don't know what your actual needs are, but I don't think WAV is ever suitable for streaming. I'd guess you should investigate some way of converting the raw output from Csound into a streaming format. 'sox' will do that sort of thing in batch mode; not sure if it will 'live stream' too.