William Petz had a problem. His company, Quiet Events, rents out over-ear headphones for parties and events all over the world. But over time, that creates a lot of wear and tear on the headphones, and eventually they break down beyond repair. The company currently has more than 1,000 headsets in its New York City office alone that are unusable. Simply throwing them away would create a whole lot of e-waste, something the company is unwilling to do, so the headphones have just been sitting, gathering dust. Petz, however, has a potential solution. The headphones can’t play music anymore, but ...