Music festivals gave me hearing loss. My best friend and I started making earplugs, and it's now a multimillion-dollar business.

Source: Business Insider

Bob Verlaat cofounded an earplug company after he started losing hearing from music festivals. Courtesy of Bob VerlaatBob Verlaat runs two companies with his childhood best friend, Nick Nijhof. Together, they designed earplugs that were stylish enough for festival goers.