A discussion on Sound

[Uncle Lou]

I have been obsessed with sound and have studied it for some time. It can be very confusing.

The decibel system is a logarithmic scale, like the richter scale, it is not linear. This simply means that 20 decibels is 10 times louder than 10 decibels and 30 decibels is 100 times louder than 10 decibels.

Or, 50 decibels is 10 times louder than 40 decibels, and 60 decibels is 100 times louder than 40 decibels. That is what is most confusing to me, How loud is 30, 40, 50, 60 decibels.

In an attempt to simplify, the following is my compilation of many sound charts and observations. These are Typical levels

Background noise of a library or sitting at your computer (the hum not the keystroke is about 30 decibels). So that is where it starts for me about 30 decibels.

A sharp human ear can detect less, but there is always background noise.

My new analog decibel meter sitting next to my computer is showing around 30 decibels. When I type, it goes up to around 45 to 50.

A conversation in a quiet room is about 50-60 decibels. This may be on the low end as 60 to 70 is not out of range for a typical conversation.
A quiet bow is around 70-80 decibels.
A lawnmower is around 90-100 decibels.

Back to quiet
Rustling leaves is around 20-30 decibels (Not wind blown leaves or walking in dry leaves)
A Whisper is around 10 to 20 decibels

I copied this from a google search
http://findarticles.com/p/articles/mi_m ... _84546930/
Typical sound levels in decibels:

Sound Chart: How Loud Is It?

Noise
Level
Sound Chart (db) Effect

Jet engine (near) 140
Firecracker 140
Rock concert 110-140
Boom box 120 Threshold of pain (125 db).
Thunderclap (near) 120
Stereo (over 100 watts) 110-125
Chainsaw 110
Jackhammer 110
Snowmobile 105
Airplane (near) 103
Garbage truck 100 Regular exposure of more than 1
minute risks permanent hearing
loss (above 100 db).
Farm tractor 98
Motorcycle (near) 90 No more than 15 minutes of
unprotected exposure
recommended.
Subway 88
Lawnmower 85-90 Level at which hearing damage
begins (85 db).
Television 70-90
City traffic noise 80 Level at which constant exposure
may cause hearing damage.
Alarm Clock 80
Washing machine 78
Dishwasher 75 Long exposure to sounds less than
75 db is unlikely to harm ears.
Vacuum cleaner 70
Hair dryer 70
Laughter 60-65
Normal conversation 50-65
Refrigerator humming 40
Quiet room 40
Whisper 30
Rustling leaves 20
0 Threshold of normal hearing

Now, what does this mean to the hunter?

Then, how does distance make these sounds more or less detectable to humans?
To Deer?


Now lets go back to how we can use this information.

Think of hearing footsteps in the dry leaves and how far away you can hear it. I think it is easily 50-60 decibels, which is approximately the level of a normal conversation.

Imagine sitting in your stand and hearing a few people talking. How far can you hear it? How far can a deer hear it. The best research I have found says deer hear 3 to 5 times better than humans. Maybe debatable, but that is what I found.

My research has indicated that the human ear can detect 20-40 decibels at 20 yards.

Here is an exercise to consider. The next time you see someone or something walking in the woods (before you hear them), note their approximate distance and conditions, and note when you hear them. This exercise will help this information help you.

And when you torture yourself to the degree I have, not just in writing this (I know it was also torture reading), You will know what we all should. There Is No Such Thing As Too Quiet!

[AC Rider]

All I can say is... WOW!

[dan]

Wow... You sure are obsessed with noise.

Why don't you send me some product pictures and pricing info, and I will add your products to our online store. Store is being built right now, should be live soon!

[DevinJD2007]

Wow Lou I can honestly say I have never seen anyone break it down as through as you just did. Great Job and very interesting thanks for sharing.

[huntinnurse]

What db is a pin drop? Lou, you really know your stuff about noise, sound and quiet. I see how the Bark Silencer came to be, more than just cutting down on the sound we hear with that noise, but what a deer hears when we don' t even see that deer and how many were coming in to us that turned another way due to a strange sound 60-100 yards away?
Impressive Lou.

[Uncle Lou]

Nurse, The pin drop ? intrigued me. I was guessing it would be 10 to 20 decibels. I was way off. Most of us think of a pin drop as quiet.

So I got out my decibel meter and took a metal safety pin. I Dropped it on a small metal container and also dropped it on the wood table. The meter was within one foot of both drops and registered ~64-68 dB on metal vs ~50-52 dB on the wood table (drop height was about 8-inches). Moving the meter about 5 feet away and repeating the above; pin on metal reduced to ~60-64 dB and the pin on wood dropped to ~45-50 dB.

I thought it interesting comparing overall sound of metal to metal vs. metal to wood. Especially, since a lot of us hunt out of metal platforms in wood trees and occasionally bump things on both our treestands and our trees.

[Tim H]

Bump!

[elk yinzer]

Pretty fascinating stuff. I for one think hunters get way overly paranoid about sound, but I've never really tried to quantify it.

I do know I've never seen a deer spook solely because of a sound. It may alert them but they always confirm it visually or by smell before they head for the hills.

Would be interested in reading more citations how deer hear. I've seen it cited that deer basically hear about the same amplitude as humans whereas this post says 4 or 5 times better.

[Uncle Lou]

I did another nerdy scientific decibel torturing discussion after this initial one. I think it was Sound Advice, I walked across the lake with the dB meter and tried to decipher how far away a deer could hear us, typical background levels, and even the sound of footsteps and stepping on sticks.

elk yinzer, I once asked a bear guide at a hunting show about the difference in deer hearing and bear hearing. He said when a deer hears a foreign sound it looks around or sniffs around for confirmation of the source, a bear on the other hand takes off.

However, I experienced what apparently you have not.

I one time spooked a buck by thunking the rifle on the wooden window of a shooting blind. He was about 100 yards away on a cold crip November morning. Sound carried directly to him at the approximate speed of 1085 ft per second. He turned around and left immediately. No biggie, it was just a classic magazine cover up north 10 pt, the likes of which I have never gotten my hands on, or had another opportunity to take. That has never happened to me again. I never made that noise again, and in over 20 years since that happened, I never saw a buck like that again with an opportunity to take it

[Uncle Lou]

Here is a link to the other sound topic. It gets buried in the deer forum. There was a lot of additional information in this thread

viewtopic.php?f=3&t=14798

[Tapeworm]

Thanks for the recent bump on this thread.

I can’t believe I never read it in here until now.

I’ve had deer hear noises but not go on alert, others instantly go into sneak off mode, some stroll over to investigate & others turn inside out trying to get the h*** out of the area.

I’ve watched some smart ones that are used to hunting pressure, sneak to bedding where they were downwind of hunters or hunters access trails.

One doe would bed close to parking lot. After the doors/tailgates shut, guys would walk off talking.

She relied on the noise for her protection.

After all was quiet she would peak out and scan the fire cut everyone left down. She already knew no strong human smells were at trucks. Then she would cross the fire cut and go drink at the creek on the other side.

One day on a just off wind I slammed truck door,tailgate & talked to my self. Then I quietly sat next to my truck peaking through the windows & she crossed at 25yds 5min later. Was hoping a buck would be with her. Didn’t shoot her but she taught me some lessons about bedding & deer movement on heavily pressured areas.