>> I believe they used a combination of sound dB meters and carbon monoxide detectors to determine approx number of people and how loud they were. > Carbon dio

>> I believe they used a combination of sound dB meters and carbon monoxide detectors to determine approx number of people and how loud they were. > Carbon dioxide* detectors, people don’t produce carbon monoxide Wouldn't smokers produce carbon monoxide when they smoked? That might be something they'd be legitimately interested in.