Deer hear noises we don’t even know we make

I told you yesterday it’s much easier to sneak up on coworkers in the office than deer in the field. But some surprising research has shown that deer might not have the hearing abilities we attribute to them.

For as long as humans have been hunting deer, and especially mule deer, we’ve assumed deer can hear much better than we can. Their ears are basically radar dishes perched on top of their heads, and they can swivel those radar dishes to pick up sounds from any direction. The sheer size of those ears has to work to gather sounds that would be inaudible to humans, right?

The answer, at least according to research conducted at the University of Georgia, is yes and no.

The scientists used deer with electrodes implanted in the deer’s heads to measure their brain activity when sounds were made. They tried sounds of varying volumes as well as frequencies, and what they found was rather surprising.

They found that deer don’t actually hear much differently than humans do, at least in the range of frequencies we hear. But deer are able to hear much higher frequencies than humans can – at least up to 30,000 hertz, while human ears top out at about 20,000. So sounds you’re making that you don’t even know you’re making might be what’s alerting that big buck to your presence. You think you’re being silent, but you’re actually setting off a silent alarm.

The good news is that high-frequency sounds don’t travel as well through the air as low-frequency noises. Even though deer can hear those ultra-high-pitch sounds, you need to be fairly close for them to pick up on them.

The bottom line, though, is that deer do hear better than humans, though maybe not supernaturally so. But what they can do is differentiate normal sounds of their surroundings from alien noises or sounds of predators. So move carefully, and try not to sound like a predator.