I never once heard of "Hooh-ah " until 5 years ago.
I first heard "HOOAH!" in Korea in the early 1990s, when the Army's ground liaison officer to the Air Force, a full bull who had the tough wiry look of 175 pounds of beef jerky, rattled the walls in a staff meeting. The Air Force three star had a bemused look on his face, didn't quite know what to make of it.