If you're here because you expect an FPGA or CPLD project, I have to disappoint you! If you're still here and may expect to see a cool 16-bit 30-channel ADC sensor chip being used, I will now disappoint you!
I want to make a crude, rough prototype that satisfies my need to achieve getting a basic sensor array to work. I want to listen with 30 microphones and display their gain in an optical way. To everyone saying this will not work the way they expect from what the title implies, I'm sorry! I don't want to track sounds or mark the spot where the noise comes from.
Idea ONE
Scan through the matrix with all 6 ADCs of an arduino on a column and 5 rows with digital pins and set AREF to the lowest (probably bad because the microphones will be too weak). Could be easily interfaced to work with the values and combine it with a video feed.
Idea TWO
use the gain built in some AVRs for some ADCs and scan each microphone one by one, still accessible for later video feed combination.
Idea THREE
Make each node individual with an attinyX5, use the gain for the microphone, an output for a LED and a serial connection for pulling the data.
Idea FOUR
go all "analog" and just visualize the gain with an LED behind the microphone.
The case
I want to design a box with tubes where the microphones are placed in, like a crude unidirectional microphone you get in those spy toys.
The software
a matrix of 6x5 blocks displaying the value of the gain in grayscale, interpolated in a second step. All generated by the data I get via (bluetooth) serial from the module inside a sketch in processing that could be turned into an app for android.
Can you use piezo elements for the microphones so you can use them as speakers too?
http://www.usna.edu/Users/math/rmm/Papers/fink2.pdf