https://blogalytics.typepad.com/files/a-technical-look-at-arbitrons-ppm-system.pdf https://blogalytics.typepad.com/files/a-technical-look-at-ar... I bet the sy

https://blogalytics.typepad.com/files/a-technical-look-at-arbitrons-ppm-system.pdf https://blogalytics.typepad.com/files/a-technical-look-at-ar... I bet the system in use looks a lot like Arbitrons system. It is near impossible to hear. And when someone does, it basically sounds like very minor league codec artifacts. Someone very familiar with a given voice, or other content, may possibly be able to tell. But an A / B test of this VS. codec artifacts will likely prove inconclusive. It is hard given clean audio to compare against. Once things have gone through a codec, all bets are essentially off. This is not to say software detector could not be used. The average phone should do fine.