Why tone matters
All languages use pitch to communicate meaning. For instance, in English, a rising pitch indicates a question (‘coffee?’), whereas a falling pitch indicates an answer or agreement (‘yes, coffee!’). But that’s a rather straightforward example of why tone matters. At least half of the world’s languages use changes in pitch to distinguish between the meaning of a particular word. Take Thai, for example, where the syllable ‘klai’ spoken with a falling pitch means ‘near’, but with a level pitch it means the opposite – ‘far’. “This use of pitch to distinguish the meaning of words is what linguists call ‘tone’,” explains James Kirby(opens in new window), a linguist and speech scientist at the Ludwig Maximilian University of Munich(opens in new window). According to Kirby, languages such as Thai, Vietnamese and Mandarin did not always distinguish words using pitch. “In modern Mandarin, huà, which means ‘speech’ or ‘words’, is pronounced with a high-falling pitch,” he says. “But 2 500 years ago, it would have been pronounced something like ‘grods’.” Why the change? With the support of the EU-funded EVOTONE(opens in new window) project, Kirby, together with a team of international researchers, hoped to find out.
Gathering data from a number of Asian languages
To start, the European Research Council(opens in new window) supported project gathered and analysed acoustic, instrumental and perceptual data from the less commonly studied languages of East and South-East Asia. Researchers further evaluated the role structural factors, such as word shape, play in the emergence of tone. They also synthesised and analysed a large collection of data from dictionaries and word lists, as well as developed specialised recordings of naturalistic speech to establish and assess a set of principles of tone change.
New findings on pitch and tone
This work led to some interesting findings. “From our work with speakers of the Mon and Khmu languages, which preserve many of the consonants that have become tones in other languages, we found that the influence of certain consonants on pitch is far less local than previously assumed,” remarks Kirby. Researchers also discovered that differences at the beginning of tones are not always perceived the same. “We found that listeners seem much more sensitive to changes at the ends of tones than they are to changes that happen at the beginning,” adds Kirby. “This was somewhat surprising as the beginning of syllables are generally regarded as more perceptually salient than the end of a syllable.” Many of the project’s findings have been published in scientific journals(opens in new window).
Understanding the factors that drive language evolution
By advancing our understanding of how languages do and don’t differ and how they change over time, the EVOTONE project has paved the way towards being able to trace historical linguistic shifts, account for contemporary linguistic differences between groups, and better understand the factors driving language evolution. “Linguistic tone is just one feature of human language, but because it is such a common and widespread one – and because it has emerged so recently in so many languages – studying its emergence and evolution helps us understand the limits of language variation and change more generally,” concludes Kirby. The project is currently in the process of making its wide range of data resources and materials(opens in new window) accessible and usable to the research community.