Hi Jared,
On Tue, 2007-03-27 at 23:20 -0500, Jared wrote:
Summary: I'm interested in capturing audio through a microphone and, in real time, determining which frequency range (from a set range of frequencies) has the maximum level. This would be used to determine which note is loudest out three notes.
[snip]
For the voting, I plan for everyone in the audience to have a small xylophone with 3. Each note will correspond to a voting choice presented by the cast. I'm going to have microphones positioned around the theatre to capture the xylophones and pipe them to a computer. What I'd then like to do through PD is determine which note was 'loudest,' meaning the most people cast it for their vote.
You could try using a multiband filter and some envelope followers, but I don't think you will be able to measure the voting very accurately using this technique.
To get slightly better results, you might want to take into account the effect of frequency on perceptual loudness (cf. Zwicker et al). You should also take into account whether or not the various votes are synchronised in time by taking measurements over some time frame, and averaging the results.
There are also other issues to consider such as the fact that not all of the voters will strike the xylophone equally hard, the resonance/absorption qualities of the room, and establishing the correct relative contribution from each microphone.
Basically, this is a difficult problem to solve, but if all you need is a 'rough idea' of how many votes have been cast, you might be OK.
Jamie