Millions of dog owners talk to, converse with or just babble at their four-legged friends every day. And despite the fact that man's best friend doesn't talk back, most pet owners seem to believe they're having some kind of impact when they hold imagined conversations with their canine friends.

But what do dogs really think of the verbal barrage? Do they think people are nuts? If so, owners with a unique voice for their pets -- usually a couple octaves higher -- might be a special kind of crazy. Or maybe not.

We were curious, so we asked a couple of pet experts just what our mutts make of our monologues.

"It's all about association," says Dr. James Serpell, director of the Center for the Interaction of Animals and Society at the University of Pennsylvania. "They might even find that reassuring. A conversational tone is associated with good things, and so dogs wouldn't be confused or upset by a prolonged discourse."

But, just because your dog reacts to the sound of your voice doesn't mean you should get carried away and imagine more people-like behaviors to dogs. "If you're humanizing and applying human behaviors to a dog, it's just not accurate," says Rachel Friedman, a professional trainer and behavioral consultant based in Cleveland, Ohio. "People often tell me, 'My dog is jealous', but dogs don't experience that."

Regardless of what dogs experience or perceive, most Americans treat dogs as part of the family. "Survey figures show that 70-80 percent of households with dogs think of them as family members," says Dr. Serpell. "The dog is a member of the family and part of the social group." And although they don't talk back to us, or speak our language per se, they do communicate with us.

"People talk to their dogs because they respond," says Dr. Serpell. "They alter their attention state. They will look at you, as if they attempt to grasp what you're saying, and they are giving positive feedback in that sense. You're not talking to the sofa -- you're talking to something."

But try as dogs might to understand, much of what people say may be falling on floppy, deaf ears.

"In my experience, people talk to their dogs way too much," says Friedman. "I think people tend to just babble at their pets, and they don't necessarily understand; people may babble to keep the animal focused, but you may be talking way more than they understand."

So maybe that's how dog became man's best friend -- because they listen no matter what, and don't tell us how ridiculous we sound.