Over history, languages change and evolve, sometimes becoming new languages. But according to researchers in the U.S. and the U.K., tracking those changes is more than just looking at words and letters.

The research team figured out a way to statistically track the changes in languages differently: by using the change in sounds, that is the specific pronunciation of words.

This method showed researchers a better way of tracing words back to their earliest usage. Their method is so exact that it allows researchers to study farther back than any other modern technique involved with studying the history of languages.

An example of these sound changes occur often in more modern languages, such as English and Latin, which both come from a proto-Indoeuropean language. The word "father" in English has a hard "f" sound at the beginning of it, but in Latin, those words still have a different sound, which sounds like a "p" as in "pater."

Researchers used math for determining the statistics involved with sound changes throughout a language's history. They found that this math-based technique offered better analysis of how language evolves over time and allowed them to trace languages back farther than ever before.

They started by studying the Turkic languages, which include about 35 different languages. They ran words from Turkic languages into a computer and found that over 70 such sound changes occur throughout the long history of the languages.

"Computers so far have mainly used the presence or absence of words with a common origin in various languages to stitch together trees that describe the descent of the various languages from a common ancestor," says Santa Fe Institute Professor Tanmoy Bhattacharya. "This has left out the vastly richer data residing in sounds, primarily because sound changes in different words are not independent, as most mutations in genetics are, for example."

Determining the differences in sounds in languages has always been considered a better way in studying the history of languages, but it's hard to do manually. However, this is the first time that someone has created a mathematical model to automatically find those changes and use probability to trace them back to prehistory languages.

"Our new method is another exciting step to understanding how languages and genes evolve," says University of Reading Professor Mark Pagel. "It will allow us to go back in time further than before, making it possible to reconstruct ancient proto-languages, words that might have been spoken many thousands of years ago."