Our team, "NYCSound": Charlie Mydlarz, Daniel Lombraña, Anita Schmid and myself. Our hack: a web-app for crowdsourcing annotations (tags) of urban sounds, built on top of the crowdcrafting framework. The idea is that participants can label the start/end times of sound sources in field recordings (e.g. "car horn", "siren", "jackhammer"), thus helping us curate a large dataset of annotated urban sounds. Such a dataset would be highly valuable for research on urban sound auto-tagging using supervised machine learning algorithms.
The hack won the "Best Science Award" and "Best Social Impact Award" - Congratulations to everyone on the team!
I'm afraid I can't actually share the hack just yet - we're hoping to turn it into a deployable system, and so it's still at internal development stages, but once it's ready I'll be sure to make a second announcement. Here's a screenshot though: