Ear to the Ground

J

joeshredd

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May 8, 2002
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Question for all you outdoorsmen...

Used to watch all the old westerns as a kid - one of the tricks to knowing if someone was traveling nearby was to "put your ear to the ground" and listen.

Don't know if that works as I've never needed to try... But...

I was watching the movie "Hidalgo" this weekend and saw a variation on this principle - stick your knife into the ground and listen to the end sticking out of the ground... :confused:

Anyone tried that? Does it work at all??
 
There's "some" merit to it...but I haven't tried outright enough to really tell you what the actual parameters are. It depends on the terrain, what you are listening for (oncoming train or mouse???), weather, altitude, etc. It also depends on how much "traffic" is around, both animal and human.

When I was in the outback in Idaho a couple years ago with Ron & Karen Hood, we were visited by an aggressive bull moose several times before he decided to charge us and scare us out. One of those visits was just around dawn, and I was sleeping on the ground outside in the open, with only a tarp between me and the ground. The moose quietly came to the edge of our camp to "check us out." I felt/heard his hooves through the ground and it woke me up. Even the dogs didn't wake up. I had my .357 Magnum out and ready -- he was about 30 ft away from me. I crawled quickly but smoothly out of my bivy bag while keeping a bead on him, and got behind a few standing thick pine trees for cover in case he charged. If I'd stayed in my sack on the ground, no amount of .357 would have stopped him in time if he had charged me at that moment. Just his momentum alone would have brought him down on me.

So, you can feel vibrations through the ground, but to what distance exactly, etc., I am not the expert in saying.

Hope this helps a little bit.

Best,

~Brian.
 
A family of four are vacationing out west and hiking.
They come upon a Native American who is lying on the ground with his left ear pressed to the earth.

The Native American says "There are two men on ATVs, heading west. They are carrying a heavy load, maybe two large deer.
One is wearing a red shirt".

The father of the family asks "You can tell all of that from listening to the ground"?

The Native American says "No. They just ran over me ten minutes ago"!


I could'nt resist,
Allen.
 
ROTF!!!! Thanks for seeing some of the humor in this Q...

Like Brian said, it depends on a lot of things...

It's just that this is the first, and only, time I've seen the use of a knife for listening - I've used glasses against a floor or wall before as a kid, and I know one can hear quite a bit thru the ground... just struck me as a neat "new" use for one's survival knife! :D
 
I'd have to be real interested in these sounds in order to stick my razor sharp polished edge survival knife blade into the ground. Hmmm but then again any excuse to sharpen is a good excuse. :D
 
I've seen shadetree mechanics use a piece of broom stick listening for ticking valves on a running engine. When you get to the bad one it'll be louder.
I don't know about the knife in the sand tho.
 
.. pesonally, I use along screwriver to listen to engine sounds. In solid ground the trick ought to work... might even work better if a person were to bite the handle (to get more efficient bone conduction of the sounds).
Enjoy!

(I'm gonna fall over laughing if I see someone actually doing this!)
 
Actually, the whole ear to the ground things works.. you may not be able to tell WHAT you hear, but it does work.

Sound travels harder (louder) and farther through solid matter. Even things like water provide a much better medium for sound to travel. A major example is tapping on a glass aquarium. To you, it simply sounds like a small tap, but inside, where the water amplifies it, it sounds like a drum.

Although I've never tried it, in theory the knife in sand thing would work, as the sand on the surface is loose, and that underneath is packed tighter.. allowing the sound to move better. The knife simply provides a bridge between that deeper sand, and your ear.
 
That depends on the frequency.High frequency sounds are attenuated more quickly. Elephants communicate long distances with low frequency[below human hearing limits] and whales do the same .In fact whales can communicate extaordinary distances ,I heard a recording made 400 miles from the whales !!
 
Also, soil disperses energy very quickly. On solid rock, I'd definitely agree that sound would transmit well through it. But on soft loamy soil or clay, it wouldn't carry very far.

So I suspect it would need to be tested on a variety of soils, from granite bedrock to sand.
 
like most things it depends, what are you listening for, horses in most of the tradition cases, so theh sound of the hooves strikning the ground. The ground then is getting the primary force of the vibration and it is a better carrier than air for that vibration. being from a time when horses were common (when most of the examples were from) a person would learn what he sound meant. much like we know how much time we have to cross a road when we hea a car coming even when we cannot see it. The mind uses the increase in volume and clarity and assumed position (learned over time by exposure to the same sound again and agian ) to judge distance speed and thus time to a certain point of intersection. An experianced person at ground listening in the time period could probably had a general idea of number, (1 2 a few several or crap its a stampede) type (size of animal), and speed.
 
The water doesn't actually amplify the sound, the sound dissapates much slower allowing it to be heard at greater distances.
While hiking once a group of riders galloped up the fire road behind us. There were around 6 or 8 horses and you could feel them coming.
Imagine a cavalry charge or buffalo stampede :eek:
 
Talk about bone conduction . . .
 
In really loud environments listening through a screwdriver or wooden “broom handle” is the easiest way to isolate sounds. It works great with earmuffs or earplugs as you are really going to the bone in your jaw or skull anyway. In these kinds of environments you can many times feel the noise “problem” in the floor with your feet even though you can’t “hear” it. In nature it would have to be a fairly big thing moving to be able to hear it very far at all. Try it with a train (after they go by) by listening to the tracks and see how long you can hear the sounds of the train.
 
The water doesn't actually amplify the sound, the sound dissapates much slower allowing it to be heard at greater distances.
Click to expand...

Actually.. we were both right.. now that I look back into my text books...

Let me try to sum up a long boring chapter on transmission..
Sound Transmission: When sound waves, particularly low frequencies, aggravate the molecules of matter. This process causes the molecules to vibrate in a similar matter to the waveform. It turns each molecule into a mini amplifier, allowing sound/vibration to be passed to the next molecule. The denser the matter, and the lower the frequency, the farther sound will pass.
Click to expand...
 
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