Dogs have quite the complex set of ears, built to maximize their hearing in ways we couldn’t possibly relate to. Puppies are typically born def, but within the first few weeks of life, they have usually developed their hearing senses beyond our own. In fact, they can already hear four times the distance of a human with normal hearing abilities once that sense starts to develop.
How is this possible?
For one, dogs have 18 different muscles used by and controlling their ears. Many of these muscles can control their ears like an antenna, allowing them to shift and move in whichever way best enables them to hear specific sounds at specific distances. Our own ears, by comparison, are simply placed on the side of our head, are more or less one consistent shape and similar size, and they don’t really move in any discernible way. It’s most clear in how these factors impact the ability to hear in comparing the design differences between breeds like German Shepherds and Bloodhounds, for example. The German Shepherd has high, pointed ears with acute hearing abilities, while a bloodhound’s floppy ears at the side of their head can actually be used to enhance their ability to smell, funneling scents toward the nose and prioritizing that sense (smell) over sound. Other factors like hair inside ears and the positioning on a breed’s head will also dictate how well they’re able to detect sounds.
The major difference in ability here is that dogs are able to detect a frequency range of 67-45,000 Hz, compared to a human range of 64-23,000 Hz. This means they are far more sensitive to lower and higher pitched sounds, which explains exactly why they can lose their minds over some sounds you might not even notice. Coupled with all those muscles in their ears, dogs have an ability to decipher where sounds are coming from in ways we can not. For humans, there is typically a general sense or approximation of where a given sound may come from. But all those muscles and such a wide range of frequencies picked up by dogs actually allows them to pinpoint more precise locations of those sounds.
All this should serve as a little bit of background info for a recent study conducted by researchers at the University of Maryland, who observed 20 dogs that were a mix of pets and working dogs like service dogs, therapy dogs, and search and rescue animals. The study was designed to explore what’s known amongst people as the “cocktail party effect” on dogs. It’s a relatable phenomenon in which you could be standing in the middle of a crowded, noisy room — a cocktail party, for example — and amidst all the chatter and busy ambient sound, you explicitly hear your name when it’s said on the other side of the room. Your name being significant in this mix of sounds because it’s one sound we often grow most familiar with. With animals, while we understand many of them have acute hearing superior to our own, there’s often confusion as to whether they can distinguish their name amongst other words because it is a familiar sound, because it often comes from a familiar voice, or if the animal even recognizes their name as a marker of their own identity. So researchers set out to learn if dogs experience the cocktail party effect in the same way we do.
The design of the study was actually pretty straightforward, for lack of a better term, placing each dog directly between two opposing speakers. With a monotone voice playing through each speaker, various names with background sounds were played. The research teams tested three different volumes levels of background noises, all similar to what we’d hear at a common coffee shop. In the midst of this, the dog’s name would come through one speaker while researchers waited to see if the dog would respond by turning its head in the direction in which its name was said.
Sure enough, the dogs did, in fact, acknowledge and recognize their own name specifically through other background noises. They only did this through the lower of the two noise levels, however, seemingly unable to hear or recognize their name with background noises at the highest (third) level.
“Studying name recognition in noisy environments is very important, especially given that service dogs often accompany their handlers to malls, grocery stores, and other noisy public places, where they must still listen and respond to commands,” Amritha Mallikarju, the researcher who led the study, told This Dog’s Life. “Noise recognition in pet dogs is important, too. If you need to recall your dog in a noisy park, you would want to know whether the background noise is so loud that your dog has trouble hearing you.”
It turns out, this is one area where our hearing trumps a canine’s. Adults, researchers reported, can hear their own name at all three noise levels while babies, whose hearing is still developing (defined as younger than a year), can only hear their name at the lower of the three noise levels in the study. Both of these observations could suggest that much of name recognition is a product of language comprehension. This thought could be backed up by the fact that the working dogs (service animals) outperformed house pets in the study. The logic here is pretty simple as well, as working dogs will obviously be more thoroughly trained than the common family dog, as well as having very specific commands they are used to receiving.
“Working dogs had more success for several potential reasons, but the most likely one is that working dogs are more regularly called by one single name, a ‘call’ name, and respond very strongly to it,” Mallikarju said. “Pet dogs often have a number of nicknames in addition to their own name, and as a result may have responded less strongly to their own name.”