African dialect uses unexpected sound

Science News, Oct 31, 1998

A sound believed not to exist in human language regularly slips past the lips of speakers of a dialect of the African language Setswana, a Georgetown University linguist in Washington, D.C., reports.

Elizabeth Zsiga made the discovery when One Tlale, a student from the University of Botswana in Zsiga's phonetics class and a native speaker of the dialect Sengwato, asked Zsiga to help her identify a sound from her language that resembles a combination of "f" and "s."

"I said, `Wait a minute, that's not supposed to exist!'" Zsiga recalls.

Current linguistic wisdom holds that combinations of hissing sounds such as "f" or "s," which are known as fricatives, only occur serially. Yet, Zsiga made spectrograms of Tlale's utterances revealing that, in words for milk, dog, new, and to belch, the sounds overlap. Zsiga found that a friend of Tlale, another native speaker of the dialect, also overlapped the pronunciations. Zsiga estimates that a few hundred thousand people speak Sengwato.