In college, some friends and I tried to build a detection system that would predict conversation lulls in public spaces - like when you're in a restaurant and i

In college, some friends and I tried to build a detection system that would predict conversation lulls in public spaces - like when you're in a restaurant and it randomly gets quiet - so we could insert premium audio ads at those moments. We never got it working, but when I see stuff like this sometimes I still think about it.