Correlations between contact points, yielded inconclusive results likely due to main line pipe material (PVC). Surfacing water from curb box led to further acoustic testing. Operation of the shut off located in the meter pit (just out of image) did not change leak signal leading to the conclusion that the leak must be between the meter pit and the main. Excavation revealed the flange on the street side of the curb valve was leaking. Further acoustic testing of surrounding areas for ground noise generated no results.