General "Did you Know?"s

[SERIOUSLY THOUGH*]

The average Professional (and highly trained) singer has a vocal range of around 1.5 octaves.

Rob Halford, original lead singer of Judas Priest, has a vocal range of 4 octaves. This is an extremely rare feat, and, had he went down a different career path, Rob could have become accomplished in almost any style of singing, not just his powerful Rock/Metal singing.
The current world record, however, for largest vocal range is a full TEN octaves, by Tim Storms. He also holds the record for lowest note ever produced vocally by a human.

HOW is 10 octaves even possible ? Surely after a while, only machines and other animals could pick it up.