Few individuals in history have had a greater impact on modern communication than Alexander Graham Bell. But in one of his early experiments conducted years before the first human voice was transmitted over his most famous invention, the telephone, it was actually his pet dog who was doing the talking.

Growing up in Edinburgh, Scotland in the mid-19th century, young Bell cultivated special interest in deafness and, in particular, the physical qualities of speech.

His father, a renowned elocutionist, had devised a system of transcribing spoken words and vocalizations into symbols representing the shape and movement of the lips and tongue formed to make them. As a child, Bell and his siblings learned to read their father's notations, and were often asked to demonstrate that intelligible words and sentences could be spoken just by following the pattern of movements.

When his mother's hearing began to deteriorate, this method took on added significance for the family -- leading Bell to explore how the "visible speech" method could help people with deafness communicate vocally despite having never heard how the words they are saying sound simply by showing them how to move their mouths.

At age 20, while staying with his grandparents in London, Bell set about testing this technique with the help of a beloved friend who had never spoken a word in his life -- his dog, a rescued stray terrier named Trouve.

Because a sustained sound, not a quick bark, would be required to produce speech, Bell's first task was to teach Trouve to start and stop growling on command, which he did by rewarding the animal with treats, writes Bryan Cummins in his book Our Dept To The Dog.

Next, he taught his to sit patiently while making the growl so that Bell could touch his muzzle. Using the training from his father's method, he knew just how to shape Trouve's mouth to produce the sounds "ma, ma, ma." In time, and after many more treats, Bell's dog was able to pronounce "Mama" in a human-like way.

Through reward and repetition, Bell added new syllables to Trouve's vocabulary. With the help of his master gently moving his mouth and chin, soon Trouve was pronouncing "ga", "ah", "ow", and "oo." Arranging these sounds in another order, "ow ah oo, ga, ma-ma," Bell had successfully taught his dog to convincingly articulate the greeting "How are you, Grandmama?"

Although Bell said that "the dog became quite fond of his articulation lessons," he was never able to get Trouve to talk just on his own -- but that didn't stop rumors from spreading that the young inventor's talking dog had become a skilled orator, which Bell himself denied.

"I made many attempts, though without success, to cause him to produce the effects without manipulation," Bell concluded. "He took a bread-and-butter interest in the experiments, but was never able, alone, to do anything but growl."

Still, the experiment would prove encouraging enough for Bell to later use the knowledge to begin a career working with deaf children, reporting that he was able to teach them new sounds much the same way. Eventually, after moving to Boston, Bell even opened a school for the deaf which helped fund his other passion for tinkering.

Interestingly, the wealthy parents of two of his students he helped teach to speak were so impressed with Bell that they decided to help financially support his other pursuits -- paving the way for the telephone and countless other inventions that would go on to change the world.