The idea sprang from NASA’s space exploration: a device that breaks up rocks without the ear-shattering roar of a pneumatic drill. Con Edison engineers are developing a “quiet jackhammer” for use in the streets of New York. Silvia Khurrum, senior engineer in Research & Development, explains the breakthrough in Con Edison’s “Current Thought” podcast. She says it hums like a vacuum cleaner. And that’ll be music to our ears.