Depends.. if you want to actually detect sound by waveform, or you
want to detect a break in a line. The break in the line can be as
simple as the game port- the  waveform means you need a noise
monitoring app, you need to break some glass similar to what you are
monitoring or get a sample at the same rate you are going to sample.
If you hear anything you need to compare.

As well- the other option is get a glass break detector that itself
drives a relay and hook that up to the game port.

One such as the GE 5812-RND

Here's a PDF

http://www.ascsecurite.ca/public/pdf/Round%20Acoustic%20Glassbreak.pdf
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