I was a member of the Sensor Sea team at Altschool. The team’s mission is to identify sensors that could be used to collect data from the physical space. One such project was Beats. It makes use of an Arduino Yun and a boundary microphone. It runs OpenWRT Linux and the microphone is plugged into the Yun’s USB port.
It records data throughout the day and simultaneously uploads the data to a local cache. This video shows how educators make use of the collected audio data: