Evolutionary research in Human Language Technologies

Prof Etienne Barnard (foreground) with Prof Roelf Sandenbergh of UP who is the coordinator of the digital@SERA projects, which include the current research in human language technologies.

Contributed by SERA

Evolutionary research in Human Language Technology (HLT) is currently being conducted at the University of Pretoria and the CSIR through digital@SERA - an IT research platform across the CSIR's Meraka Institute and its Defence, Peace, Safety & Security business unit, and the University of Pretoria's Faculty of Engineering, the Built Environment and Information Technology.

Currently, the research focus is on speech synthesis, speech recognition and machine translation. While widely deployed in the developed world, the value of these technologies for adoption and application by the developing world is only now being realised. The team involved in this research is led by Prof Etienne Barnard, an extraordinary professor in UP's Department of Computer Science and a research scientist at Meraka.

Developments in this field can provide information to people who would otherwise not easily be able to access it, such as speech synthesis or Text to Speech (TTS) technology. One of the first projects has been a synthesis of isiZulu where the system can now produce fairly understandable, although not yet natural-sounding, synthesis.

Speech recognition is a more complex task, as these systems need to recognise different languages and voices, as well as nuances such as dialects and accents. "Even the best systems in the local languages are perhaps 80% accurate, while the best English systems produce an accuracy of about 98%", says Barnard. The HLT group aims to develop a local speech recognition system that works as well as English systems within the next five years.

Two systems have already been developed to a level where people are starting to use them in practical applications. The first of these is "OpenPhone" - a telephone-based system for a local NGO active in HIV/AIDS prevention and treatment. With a HLT speech synthesis system connected to the NGOs main information system, its field workers can telephonically access up-to-date information on new treatments from remote locations.

The speech synthesis systems have also been integrated Meraka's National Accessibility Portal (NAP) to enhance the independence of persons with disabilities. As part of NAP the speech systems allow people with speech disabilities to communicate via synthesised speech. The same technologies can similarly be used to enable screen readers in local languages for people with vision disabilities.

digital@SERA has always focused on facilitating collaboration and influencing researchers to direct their research in useful directions. In addition, an important goal is to extend the research pipeline. This requires significant investment, as it can take up to three years to get the pipeline to a sustainable level, but there is a lot of interest amongst team young researchers at UP in the potential of the HLT field. "Growth of this pipeline is something that we don't have enough of in South Africa, and it is encouraging to see young people getting excited it", according to Barnard.

For more information contact Prof Etienne Barnard at 012 420 2981/4035 or visit the HLT group's web pages at www.meraka.org.za/hlt.

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