The mailman was on the porch, and Diva was out of her mind.

“Get out of here!” she shouted, and, obligingly, the letter carrier hustled off.

All right, my mouthy Rhodesian Ridgeback didn’t actually say those words. But if she could have, she would have, according to the Bow-Lingual, a “dog translator device” that deciphers woofs, growls and yips into plain English using “voice print technology.”

Effecting this interspecies chit-chat is relatively easy: First, you attach the lightweight microphone/transmission unit to your dog’s collar. When the woofing starts, it transmits data to a PDA-sized handheld unit, which then “translates” those voice patterns into one of 200 phrases reflecting six basic emotions: sad, frustrated, needy, happy, self-expressive or on guard.

The Bow-Lingual has been a hit in its native Japan since it debuted a year ago, and has been available in this country for several months, with a suggested retail price of $120. Time magazine named the overseas version one of “The Coolest Inventions of 2002,” and in May, Japanese Prime Minister Junichiro Koizumi presented a pair of Bow-Linguals to Russian President Vladimir Putin, presumably to use on his poodle and Labrador retriever.

But does it work?

In a word: sometimes. Consider Blitz, my male ridgie, who thinks it is his birthright to share the new sofa with me. If there is no room, he will stare at my supine self and whine. Repeatedly.

About half the time, the Bow-Lingual interpreted his vocalizations correctly: “Can’t you hear me?” “That’s not what I want!” and “Just listen to me!” were right on the mark. But no matter how snuggle-deprived Blitz was, “I might bite!” was a little over the top, as was “Are you my friend or my enemy?”

“There’s a little bit of science, and a lot of great marketing” in the Bow-Lingual, says Stanley Coren, a professor of psychology at the University of British Columbia in Vancouver and author of “How to Speak Dog” (Free Press, $24). “There’s a sort of animal Esperanto that goes across all species. Certain dimensions — namely, pitch, the duration of sound and how frequently it’s repeated — are used by animals to convey the same thing.”

A high pitch, for example, communicates fright or playfulness; low-pitched sounds are threatening and aggressive. Sounds of short duration are usually based on something unexpected, while long sounds often indicate tension. And the more frequent the repetition, the more likely an animal is to be excited.

What the Bow-Lingual does, says Coren, is “take these basic dimensions and turn them into cute phrasings.”

Problem is, dogs are far more eloquent with body language than the verbal kind. “Think of their wild ancestors, wolves,” Coren says. “If they are out on a hunt, and the leader sees a deer, he’s not going to yell to the pack, because they’ll lose lunch.”

Takara Corp., the company that manufacturers the Bow-Lingual, notes that false readings are possible, especially in areas with a lot of high-frequency interference.

But, Coren adds, there are other “contaminants” that can skew results: While the Bow-Lingual asks you to input your dog’s gender, breed and nose length, factors such as a dog’s age can change excitability levels, and as a result, the translation.

If you think cats might be an easier species to decipher, think again. The Meow-Lingual debuted in Japan in late November, and should be headed for these shores sometime next year. “But even as a toy, the cat one is apt to be considerably less useful,” says Coren, “because cats are much less social, and so their vocal repertoire is much more limited.”