Dogs recognize their owner's voice. And not just their owner's; they can recognize a number of individual voices of people who they are familiar with. This is a remarkable feat in some ways: They can distinguish their owner's voice from seemingly similar voices—say, other deep female voices of similar timbre. Dogs seem to treat their owners (or at least their voices) as unique.
The standard story about why this is so is that the evolutionary process that has shaped dogs' behavior is special inasmuch as dogs have been selected for their interaction with humans. Dogs have been human companions for tens of thousands of years and, to put it somewhat bluntly, those dogs that survived and reproduced were better at adapting to the human social environment. The others were left by the wayside.
This dog-human co-evolution explains a number of important cognitive abilities that dogs have and other animals don't; for example, certain aspects of the rule-following behavior that dogs often display without any (or little) training as well as their relatively well-developed impulse control. So it is tempting to explain anything that is special about dog cognition in terms of this selection by the human social environment.
Recognizing the owner's voice would seem to fit this general explanatory scheme. Given that dogs have adapted to the human social environment, recognizing individual humans' voices was an adaptive trait: Those dogs who could do so have enjoyed a selective advantage. So dogs gradually got better and better at this and now they are excellent at recognizing individual human voices.
But new research on wolves casts doubt on this seemingly simple and straightforward story. Wolves have been an important contrast case for any findings on dog behavior as dogs have evolved from wolves and wolves have not been anywhere close to the kind of human social environment that shaped dog behavior. For example, wolves don't display the penchant for rule-following that dogs have and they are distinctively worse at impulse control. This is why we can make inferences about how these abilities were the result of the interaction with the human social environment.
Crucially, as these recent studies show, this contrast is not there when it comes to the ability to recognize individual human voices. Wolves, just like dogs, can, in fact, recognize individual human voices. The experiment, which included 24 wolves, showed that these wolves quickly lost interest if they heard voices they had encountered for the first time, but if they heard a voice that they had encountered before (such as the voice of the personnel at the wildlife park), they behaved very differently: They remained engaged, pricked their ears, and raised their head. In other words, they did what every dog does when they hear their owners.
Wolves are not alone in this ability. Cats have been shown to be very discerning about human voices; the same is true of gorillas. So it seems that when your dog recognizes your voice, this has nothing to do with the tens of thousands of years of dog-human interactions as this ability apparently predates any such interaction. But this does not make you any less unique in your dog's eyes.