from Things To See In Springtime
Can you hear like an owl? An owl can find his prey by hearing after dark. His ears are wonderful. Let us try if yours are.
1. Watch-test. First, you must be blindfolded, and in some perfectly quiet place indoors. Now have the Guide hold a man's watch (open if hunting-cased), near your head; if you can hear it at 40 inches, measured on a tapeline, and prove that you do, by telling exactly where it is, in several tries, your hearing number is 40, which is high. If at 20 inches, it is low (20 pts.); if at 60 inches (60 pts.), it is remarkable. Anything over 50 points means you can hear like an owl. In this you go by your best ear.
2. Pindrop-test. Sometimes it is difficult to get a good watch-test. Then the trial may be made with an ordinary, silvered brass stick-pin, 1-1/8 inches long, with small head. Lay the pin on a block of wood that is exactly half an inch thick. Set this on a smooth polished board, or table top of hardwood, not more than an inch thick, and with open space under it. Set it away from the edge of the table so as to be clear of the frame and legs. After the warning "ready," let the Guide tip the block of wood, so the pin drops from the block to the table top (half an inch). If you hear it at 35 feet in a perfectly still room, your hearing is normal, and your hearing number is 35. If 20 feet is your farthest limit of hearing it, your number is 20, which is low. If you can hear it at 70 feet, your number is 70, which is remarkable.
You can use either the watch-test or the pin-test. If you use both, you add the totals together, and divide by 2, to get your hearing number.