This would be useful for anybody who might need to find the source of a sound quickly, such as a hunter, soldier, or somebody working around machinary that could fail, causing a safety issue. I'm not sure how obvious it is to anybody. I just made the connection recently because I go for long walks at night out here in the country often and I cut the walks short if I think a skunk or possom are nearby.

Here's what you do. If you hear a sound, immediately turn your head in the general direction and don't move or look around, just stare. The next time the sound happens, move your eyes closer to where you think the sound came from. Keep doing that until you find the source. You don't want to keep moving your head because that changes the way the accoustics are sensed by your ears. You also want to avoid moving your eyes too much because that uses brainpower you could be allocating to hearing the source again. With practice, you'll be able to find the source by the second time you hear the sound, sometimes even after the first sound. You may have noticed dogs do this instinctively since they rely on their hearing more than humans.

Another little trick I learned was how to spot something in the dark. It's difficult to see something in the dark that isn't moving by looking directly at it. If you move your eyes around slightly in the general direction of the object you're trying to see, the silhouette sometimes pops out at you.

So, next time a sniper is shooting at you in the dark, you may be able to make eye contact with him before he blows your brains out.