Most of the people in a choir at Ryerson University in Toronto have joined a study testing how practicing music might help people with hearing loss handle noisy environments better.
Sgt. Jessie Bacon uses the Tactical Communications and Protective System to relay information to his squad in Fort Bliss, Texas. About 20,000 of the devices have been deployed so far.
Sgt. Betty Boomer/U.S. Army
The current record holder for loudest crowd in history are the fans of the Seattle Seahawks, who cheered so loud that they induced a mini-earthquake. But that level of noise can permanently damage fans' hearing.
Musician Jake Orrall performs onstage at the Coachella Valley Music & Arts Festival on April 14. Temporary hearing loss following concerts and other loud events may protect our ears from more permanent damage.
Frazer Harrison/Getty Images for Coachella