Brian Johnson

The legendary AC/DC frontman had to abruptly step away from the band's world tour in 2016 after doctors warned him he faced total, permanent deafness.

His hearing loss was accelerated not just by stage volume, but by a ruptured eardrum from racing cars without protection.

Credit advanced, cutting-edge inner-ear monitor technology for allowing him to return to the stage safely, with the singer reflecting: "I could hear the 30-year-old Brian Johnson again."