This looks like a very interesting project. If you're into audio measurements, this project might also interest you.
From the Pmillett website...
Most of us DIY audio types have been using PC sound cards to make
measurements. There are excellent, inexpensive programs available to do
test and measurement of audio equipment available. Personally I use Audiotester.
If you've been around my web site you've seen FFT plots generated that way.
What has always been lacking is a decent interface between the sound card and
the device under test (DUT for you geeks). There has been much discussion
in forums like DIYaudio about this, and many proposals and circuits shown, but
so far I've not seen anything implemented.
The problem with sound cards is that they are designed for fixed line-level
inputs and outputs. Depending on the card this may be between 1V and 5V
RMS maximum. They are also not tolerant of overloads - accidentally deliver 20V
into your sound card input and you will most likely be looking for a new sounds