Chances are you're talking too loud, but not grunting loud enough. Here's what the science says about the auditory capabilities of whitetails
We shell out good money on scent-control clothes and a concoction of soaps and sprays to knock out our man-smell. We wear our camo and hide as best we can from a buck's sharp eyes. All are good and critical strategies. But what if a buck hears you?
Or put another way, if you're trying to rattle, grunt, bleat, or snort-wheeze, what if he can't hear you?
Whitetail Ears, Explained
Scientists have found that the auditory canal openings in a deer's ears are about the same size as those in our ears. But since a deer's ears are larger, some 7 inches long and wider than ours, they pick up and funnel more sound waves. You've probably seen this in the woods: Deer come moseying along, stop, raise their head and start flicking and rolling their ears, back and forth and to the side. They are trying to home in on and sort out various noises in their habitat. If a doe or buck senses an unnatural and potentially dangerous sound, it will turn its head in that direction and look harder, sniff, and listen some more.
If you made that sound — cracked a stick with your boot or clinked your bow on your stand — freeze, because a deer is onto you. If the animal sees or smells you, it will put two and two together and scram. On the other hand, if you stay still and undetected, the deer will usually go back to its business. You can fool a deer's ears by playing your cards right, whether you're walking in the woods or hunting up in a treestand.
How Well Do Deer Hear?
You assume that with those twirling ears, whitetails naturally hear better and farther than we can. But not really. In a study, researchers at the University of Georgia's Deer Lab put does and bucks, ages 6 months to 4 years, in sound chambers, attached electrodes to their heads, and monitored their brain waves to see how the animals responded to different sounds and frequencies.
The frequency of sound is measured in hertz. Studies show that a healthy human can perceive sounds from as low as 20 to as high as 20,000 hertz. Our best and most sensitive range is between 2,000 and 5,000 hertz. The Georgia researchers found that whitetails of all ages hear best at moderate frequencies of 3,000 to 8,000 hertz. To put perspective on it, both our normal speech and most deer vocalizations (grunts, bleats, and blats) fall within these frequency ranges. While deer vocalize at lower frequencies than we talk, they hear similarly.
One big takeaway from that study: The scientists point out that human speech is a moderate-frequency sound that can travel far and is well within the peak hearing range of deer. Keep that in mind as you're in the tree, calling out shooting lane limbs to trim to your buddy.
But assuming you whisper, from how far away can a deer hear the usual noises that go into a hunt, like sticks cracking, rustling leaves, and the clink of a bow against a treestand? Try this experiment, best done on a calm, windless day. As a buddy hangs steps and a stand in a tree, you walk straight away and stop at various intervals, until you can't hear those metallic noises anymore. Walk back to the tree and count your steps as you go. Depending on the terrain and density of cover, it might be 75 yards or 100 or more.
Once he's done setting the stand, have him climb down and walk around the stand a few times, shuffling leaves; you move away until you can't hear the sounds anymore. Again, count the steps and gauge the distance. Since the science shows that deer hear about like humans do, this will help you understand how far deer can hear normal hunting sounds, and what you can and cannot get away with, noise-wise, on your hunts.
What About Deer Calls?
The Georgia researchers also analyzed different grunt calls, and they found that the call companies had done a pretty good job of creating realistic grunt tubes. All the calls they tested produced similar sounds, with the strongest frequency range between 3,000 and 4,000 hertz — well in tune with a deer's hearing.
They went on to point out that while most grunters sound true, they need to be blown fairly hard for deer to hear them. Most hunters blow too lightly, especially when blind calling from a stand with no deer in sight. Don't be afraid to crank up your calling, within reason. A buck must hear your calls before he can even think about responding.
The Curiosity Factor
Years ago, noted wildlife researcher Leonard Lee Rue, who observed and recorded tens of thousands of deer in his studies, theorized that a whitetail's hearing is directly linked to what he called a bump of curiosity. Rue said that if a deer hears a normal woods noise (like an animal walking in the leaves) but cannot see or smell the source of that sound, sometimes it will actually come closer to investigate.
I have seen this play out many times in the woods. You're slipping along and walk up on a deer that has not seen or smelled you. You take a few more steps and freeze behind a tree. The deer hears those last footsteps and looks your way, ears rolling, homing in, trying to sort out the sound. Sometimes, the animal turns and walks toward you, and once in a blue moon you might get a bow shot if you freeze and stay still. In my opinion, that same curiosity factor plays a big role in why many, if not most, deer that hear your grunts or rattles respond.
So with bow seasons set to open in a few weeks, and a deer's hearing capability fresh in mind, remember to sneak to your stand. Whisper to your buddies. Do everything you can to avoid the metal bangs and clangs of deer. But also, if you're going to call, don't be shy about it.
It's hard enough to get past a buck's nose and eyes. But if you're smart and careful, you can play a buck's hearing right into your favor.