[Harp-L] Differences between ears

[David Payne <dave@xxxxxxxxxxxxxxxxxxxxxx>]

There is a book about the Battle of Outpost Harry in the Korean War by James Evans, who was commander of Company A, 5th Regimental Combat Team, a company of about 180 men who successfully defended the outpost from an attack of 15,000 Chinese in June 1953. My grandfather was the company's radio operator. 
My grandfather was an incredible musician and he had a remarkable ear. Better than mine. 
The scene I'm about to describe was from the night of June 11 - 12, 1953. Evans, my grandfather and a jeep driver were traveling to relieve the company defending the outpost. They were, at this point, separated from the rest of the soldiers in the trucks behind them. Technically, the book does not say which of the two this soldier was, but I know how good my grandfather's ear was and thus presume it was him and will explain this as if it were him. 
As they were traveling this Korean backroad between the American and Chinese lines (the outpost itself was between the lines), these Chinese shells start pouring in. They jump out of the jeep and dive into a ditch. 
Evans explains:
"One soldier in our group had remarkably good ears. Even kneeling in the ditch, he could hear the incoming. Before I could hear anything, he would cry out "Here comes another one!" About a second later, my own ears could pick up the roar. Then, we were shaking and ducking again." 

The muzzle velocity of Chinese 122mm howitzer is around 1,800 feet per second - that's faster than sound, so the shell gets to you before the sound of the gun firing. Let's say that by the time the shell got near them, it had slowed down to 1,300 feet per second. About the fastest I can say "here comes another one" is about a second or so. That's two seconds, minimum and not counting reaction time, etc.
Hearing it just two seconds early means that shell traveled for at least half a mile and my grandfather could hear that shell move while everyone else heard nothing.
My vision isn't that great, I'm farsighted. I've been wearing bifocals since I was 20 years old, but I also shot a deer once at 300 yards with no scope, just the stock iron sight on an Enfield rifle. I can see really well far off, but I can't see a dang thing up close without my bifocals - I can barely read my watch without them. 

I can't imagine hearing being much different than vision in that regard. I would imagine that just as we all see differently, we hear differently, too. 

If I can make it SPAH next year, I would certainly be happy to guinea pig myself on this stuff. I would really like to do a brass comb vs plastic or something test.

David Payne
www.elkriverharmonicas.com
www.hetrickharmonica.com